Beetle That Looks Like an Ant: Discovering Nature’s Master of Disguise

Beetles are an incredibly diverse group of insects, representing the largest order of animals on Earth, with nearly 30,000 species known in the U.S. and Canada alone. Among this vast array of species, some beetles have evolved to resemble ants – a phenomenon known as myrmecomorphy. This fascinating adaptation allows these beetles to blend in with ant colonies, providing them with protection from predators and access to resources.

Myrmecomorphic beetles exhibit a range of physical traits and behavioral patterns that mimic those of ants. For example, they may have slender, elongated bodies and smaller elytra (wing covers) that resemble an ant’s segmented body. Additionally, these ant-mimicking beetles may move and behave in ways that further enhance their disguise, such as walking in a zigzag pattern like ants or even producing scents that mimic ant pheromones.

The benefits of ant mimicry for these beetles are numerous, including enhanced protection from predators that avoid ants due to their aggressive nature or unpalatable taste. Furthermore, some species of ant-mimicking beetles may gain access to food resources within ant colonies, such as larvae or honeydew produced by aphids.

The Ant-Like Beetle

Physical Characteristics

The ant-like beetle is an interesting insect that closely resembles an ant in appearance but is actually a type of beetle. These insects can be found in various colors like black, brown, red, green, and yellow. In terms of size, ant-like beetles are comparable to ants, making them quite small.

Some distinguishing features of ant-like beetles include:

  • Wings: Usually present, while ants may or may not have wings
  • Body Shape: Typically more rounded or oval compared to ants’ slender, segmented bodies
  • Antennae: Elbowed in ants, while ant-like beetles generally have straight or slightly curved antennae

In certain species, the exoskeleton of the ant-like beetle can also mimic the texture and patterns found on ants.

Ant Mimicry

Ant-like beetles employ mimicry as a survival strategy in their habitat. By resembling ants, they can avoid predators who may avoid ants due to their aggressive nature or unpleasant taste. These insects achieve this mimicry through their coloration, body shape, and other physical characteristics.

Feature Ant-like Beetle Ant
Size Comparable to ants Varies with species
Color Black, brown, red, green, yellow Black, brown, red
Body Shape Rounded or oval, segmented Slender, segmented
Wings Usually present May or may not be present
Antennae Straight or slightly curved Elbowed

In conclusion, ant-like beetles are an intriguing group of insects that have evolved to closely resemble ants in order to deter predators and survive within their habitats.

Types of Ant-Like Beetles

Longhorn Beetles

Longhorn beetles are a diverse group of beetles sharing some common characteristics, such as their long antennae and elongated body. Examples of Longhorn beetles that resemble ants include the Asian longhorned beetle and the white-spotted pine sawyer.

  • Features:
    • Long antennae
    • Elongated body

Comparison Table: Asian Longhorned Beetle vs. White-Spotted Pine Sawyer

Feature Asian Longhorned Beetle White-Spotted Pine Sawyer
Color Black Brown
Antennae Straight Segmented

Ant-Like Stone Beetles

Ant-like stone beetles are small, ground-dwelling beetles known for their ant-like appearance. The family Anthicidae includes several species resembling ants.

  • Features:
    • Small size
    • Ant-like appearance

Ant-Like Leaf Beetles

Ant-like leaf beetles belong to the case-bearing leaf beetle family. Distinct for their resemblance to ants, species such as Aulacoscelis spp. exhibit this trait.

  • Features:
    • Ant-like appearance
    • Case-bearing

Ant-Like Flower Beetles

These beetles are part of the Erotylidae family – their ant-like appearance is characterized by their narrow abdomen and distinct color patterns. An example is the genus Megalodacne.

  • Features:
    • Narrow abdomen
    • Distinct color patterns

Rove Beetles

Rove beetles are members of the family Staphylinidae. Known for their flexibility, they often raise their abdomen similar to the way ants do. Examples include the large rove beetle, Dalotia coriaria.

  • Features:
    • Flexible abdomen
    • Ant-like posture

Comparison table of ant-like beetles

Beetle Type Example Unique Feature
Longhorn Beetle Asian Longhorned Beetle Long antennae
Ant-Like Stone Beetle Family Anthicidae Small size
Ant-Like Leaf Beetle Aulacoscelis spp. Case-bearing
Ant-Like Flower Beetle Megalodacne Color patterns
Rove Beetle Dalotia coriaria Flexible abdomen

Ecological Roles

Diet & Feeding Behaviors

The velvet ant, which is actually a beetle that resembles an ant, has a diverse diet. Primarily, it feeds on:

  • Small arthropods: Examples include spiders, true bugs, and stick insects.
  • Organic materials: Dead wood and leaves are common sources.
  • Fungi: Some species of velvet ants are known to consume fungi.

It has also been observed feeding on nectar from plants, pollen, and honeydew produced by aphids.

Reproduction & Life Cycle

The velvet ant has a unique life cycle, and its reproduction process involves:

  1. Mating: Males and females mate, usually during the warmer months.
  2. Oviposition: Female velvet ants lay eggs using their ovipositor, often targeting other ant species, such as carpenter ants and worker termites.
  3. Larvae: The eggs hatch and the larvae feed on their host ants or termites.

Habitats & Distribution

Velvet ants can be found in various habitats across the globe, from deserts to gardens. Despite their diverse distribution, they are not native to Antarctica. Some typical habitats include:

  • Trees: Velvet ants often create galleries in dead wood using their strong mandibles.
  • Gardens: They live among plants and make use of leaves, fruits, and seeds.
  • Deserts: Velvet ants have adapted to survive in harsh environments, with their hard exoskeletons and ability to tolerate high temperatures.

In summary:

Attribute Velvet Ant Carpenter Ant Stick Insect
Diet Small arthropods, organic materials, fungi Insects, honeydew, plants, fungi, nectar Plant leaves
Reproduction Host ant or termite species Queens lay eggs in colonies Oviposition, solitary
Habitat Trees, gardens, deserts Wood, trees Trees, leaves
Unique Characteristics Painful bite, thin waist, toxin in some Strong mandibles, break down cellulose Camouflage, immobile when threatened

Interactions with Ants and Other Species

Ant Mimicry in the Ecosystem

Ant mimicry is a widespread phenomenon found in various species, including:

  • Spiders
  • Sawflies
  • Crickets
  • Grasshoppers

These creatures mimic ants to gain protection from predators or to infiltrate ant colonies for food and shelter.

Predatory Relationships

Some ant-mimicking species, such as the spy beetles, have evolved chemical and acoustic mimicry to infiltrate ant colonies. They feed on both ants and their larvae without being detected as intruders.

Examples of predatory interactions include:

  • Velvet ants: a type of wasp that mimics ants in appearance and behavior
  • Spiders: Some species that resemble ants to deceive potential predators while hunting for food

Coevolution with Ants and Termites

Ants and termites share ecosystems with various species, such as:

  • Bees
  • Cockroaches
  • Aphid-tending ants

Their coexistence often necessitates a level of adaptive evolution between them.

Comparison between Ants and Termites:

Feature Ants Termites
Antennae Elbowed Straight
Waist Thin (“wasp waist”) Broad
Social behavior In colonies In colonies

Parasitic Species

Not all interactions with ants are beneficial. Some parasitic species, like drainage bugs, exploit ants’ resources to survive.

Characteristics of parasitic interactions:

  • Infiltrate ant colonies to access food and shelter
  • Potentially harm the host ant population
  • May introduce diseases or toxins to the colony

Recognizing the Differences

Beetles vs. True Ants

To distinguish between beetles that look like ants and true ants, keep an eye out for specific features. While both might have similar body shapes and color patterns, you can spot some significant differences, such as:

  • Antennae: Ants have elbowed antennae, while beetles possess longer, straighter antennae.
  • Wings: Flying ants have a pair of larger front wings and a smaller pair of hind wings, usually tinted brown. Beetles usually have wing covers called elytra.
  • Waist: Ants exhibit a pinched or “wasp-waist,” while beetles have more full-bodied appearance. For example, ant-like beetles often display metallic green or blue colors and have larger bulging eyes.

Similarities and Differences with Wasps and Flies

It’s essential to understand the similarities and differences between beetles, wasps, and flies for accurate identification:

  • Wasp similarities: Both wasps and ant-like beetles can exhibit bright colors and a pinched waist.
  • Fly similarities: Similarities between flies and beetles may include a small and flattened body shape. For instance, foreign grain beetles are reddish-brown with a hard shell and can be confused with fruit flies or gnats.
Insect type Antennae Wings Waist Body Colors Eyes
Beetle Longer, straight Elytra or wing covers Full Metallic green/blue, reddish-brown Larger, bulging
Ant Elbowed Larger front wings, smaller hind wings Pinched Black, brown, reddish
Wasp Pinched Bright colors
Fly Small, flattened, reddish-brown

Other Insects that Mimic Ants

Some insects evolve to mimic ants for various reasons, such as survival through camouflage or to escape predators. A few examples of insects that mimic ants include:

  • Velvet ants: Known for their painful sting, velvet ants are actually wasps that imitate ants with their hairy bodies and similar color patterns.
  • Pretermites: These insects closely resemble ants but are actually a type of termite. They can be distinguished by their straight, bead-like antennae as opposed to ants’ elbowed antennae.

In conclusion, recognizing the differences between beetles that look like ants, true ants, and other insects can help you accurately identify various species. Pay attention to features such as antennae, wings, waist, body shape, and colors to differentiate between these insects.

Reader Emails

Over the years, our website, whatsthatbug.com has received hundreds of letters and some interesting images asking us about these insects. Scroll down to have a look at some of them.

Letter 1 – Oil Beetle

 

Subject: WTB
Location: Powder Springs, Ga
December 9, 2016 6:49 pm
Have no idea what this is. Found in Powder Springs, GA. My son and I admired it for a while then we let him go free.
Signature: Lataine III

Oil Beetle
Oil Beetle

Dear Lataine III,
This is an Oil Beetle, a species of Blister Beetle in the genus
Meloe.

Letter 2 – Oil Beetle

 

oil beetle
my boss [runs a tree-trimming, spraying etc company] found a bug … i’ve attached a photo – not the best photo = i took it. do you think it is an "oil beetle"? we are located in stockton new jersey, but do tree work in new jersey and pennsylvania, so is it possible that oil beetles are in our area?
thanks for your help?
lynnie

Hi Lynnie,
Yes, this is an Oil Beetle. They are also known as Short Winged Blister Beetles and are in the genus Meloe. They are found in your area. According to the Audubon Guide: “If disturbed, this beetle feigns death by falling on its side. Leg joints exude droplets of liquid that cause blisters.” We are hoping your photo shows this feigning death behavior and is not the result of extermination.

they did not exterminate it … they found it, and wanted to know what it was. they actually thought it was dead and brought it back to the shop. next morning it was moving. i had just put it out on the paper with the ruler to take the picture so mr beetle could just be faking it again. thanks for your help. i will share with my boss in the morning.

Letter 3 – Oil Beetle

 

queen ant?
Hi,
I saw this ant in NE Alabama just last week. We got a picture of it, but of course, it was so blurry you couldn’t even make out its shape. However, I ran across this photo someone had taken, and it is the same creature we saw. It was almost two inches long, most of which was abdomen. Is it for sure an ant and can you tell which one specifically? Thank you! And by the way, I love this website!
Best regards,
Mary Shew

Hi Mary,
It might look like an ant, but it is a Short Winged Blister Beetle or Oil Beetle, Meloe angusticollis.

Letter 4 – Oil Beetle

 

Subject: On my house
Location: Louisville ky
October 25, 2012 11:01 pm
Hey, this soft boddied insect with a large abdomen who was about 1.5 inches long was on my house. I tried to tap it off into a small box to move it into my yard, but it was fragile and I smashed it a bit. Very docile. Ideas?
Signature: Michael S

Oil Beetle

Hi Michael,
Your Oil Beetle is in the Blister Beetle family and it should be handled with caution.  Blister Beetles can exude a compound cantharidin that can cause blistering in human skin.

Thanks for the quick response.  Luckily I didn’t touch it directly, and though its abdomen smashed a bit and oozed some bright yellow, it seemed ok walking around in our yard.  I removed it into a small cardboard shipping box with the edge of an envelope.  My 3 year old was interested in touching it, as it was right by the front door of our house.  Thanks for identifying it.  I sent it to some local farmers who didn’t know what it was.
Thanks,
Michael S

Letter 5 – Oil Beetle

 

Subject: Invasion fo the giant WTHs
Location: SE Michigan
November 3, 2012 9:13 pm
Spotted four of these in my backyard in early November. Two pairs in widely-separated locations. About an inch long, black-green in color, big fat abdomens, small wings/wing covers. Very sluggish. What the heck are they?
Signature: Fred Robinson

Oil Beetle

Hi Fred,
This is an Oil Beetle, a type of Blister Beetle in the genus
Meloe.

Letter 6 – Oil Beetle

 

Subject: Blue Mud Wasp – Queen?
Location: West Virginia
September 23, 2013 9:06 am
Hi bugman,
This summer we’ve had these odd wasps on our pool house screen window, they didn’t seem to be aggressive at all. They were slightly metallic blue and their wings fluttered different from most wasps. They left just black spitted stuff on the window frame and they seem to be gone now. The bug in the photo was found just a few days ago and I’m wondering if she is their queen. She was about 30 yards from where the other ones were. I found her having a hard time climbing up the brick of our house. She/it didn’t seem to have wings & I didn’t see her fly at all. Any ideas?
It is nearly fall here in the lower lands of West Virginia.
Signature: Maria

Oil Beetle
Oil Beetle

Hi Maria,
Your insect is an Oil Beetle, one of the Blister Beetles in the genus Meloe.  People often mistake them for queen ants.  Blister Beetles should be handled with caution as they can exude a compound known as cantharadin that is known to cause blistering in human skin.

Hi Daniel,
Wow, glad I didn’t play with it! 😉  So I guess the wasps having the same metallic look is just a coincidence.  Thanks!
Maria

Letter 7 – Oil Beetle

 

Subject: What’s this black ant beetle bug?
Location: Peekskill, NY
October 11, 2013 4:24 am
What oh what is this curious bug? My daughter and I discovered it while heading out on a nature walk. It is the size of a quarter. I was on one side of its wooden perch and my daughter was on the other side. The bug slowly turned its head towards me, then my daughter, then back to me… It was creepy! Never seen this bug before and I’d like to know what it is.
Thank you!
Signature: Casey Nugent

Oil Beetle
Oil Beetle

Hi Casey,
This is an Oil Beetle in the genus Meloe, one of the Blister Beetles.  The modified antennae indicate that this is a male Oil Beetle, according to BugGuide.

Letter 8 – Oil Beetle

 

Subject: Large black beetle looking?
Location: Central New Jersey
October 22, 2013 5:25 am
I’ve seen this bug earlier in the year during summer i believe but just noticed them more and more. I think its the same bug that eats my dogs poop and lives in the ground. Gross! What is it?
Signature: Jimbo

Oil Beetle
Oil Beetle

Hi Jimbo,
This is an Oil Beetle, one of the Blister Beetles in the genus
Meloe.  To the best of our knowledge, they do not eat fecal matter.  We believe you are confusing it with a Dung Beetle.

Letter 9 – Oil Beetle

 

Subject: Large black bug
Location: Southern Ohio
November 7, 2013 8:16 pm
This was on the side of our house. I have lived here all my life and haven’t seen one. Any idea what it is?
Signature: Jennifer F.

Oil Beetle
Oil Beetle

Dear Jennifer,
We often get identification requests for Oil Beetles in the genus
Meloe from your part of the country at this time of the year.  Handle with caution.  Oil Beetles are Blister Beetles and they can exude a compound known as cantharidin which is known to cause blistering in human skin.  It is also the substance found in the aphrodisiac Spanish Fly.

Letter 10 – Oil Beetle

 

Subject: What IS this thing?!
Location: Memphis, TN
February 14, 2014 5:51 am
I found this crawling on the threshold of my front entrance tonight when I got home from work. I was shocked, because today was our first relatively warm (high above 40) day in about three weeks. So I brought her inside and had my son take some pictures. I thought maybe a queen ant, but figured you all could tell us for sure.
Signature: Editormum

Oil Beetle
Oil Beetle

Dear Editormum,
This impressive creature is an Oil Beetle, one of the Blister Beetles in the genus
Meloe, and you can see BugGuide for additional information.

Oil Beetle
Oil Beetle

Letter 11 – Oil Beetle

 

Subject: Beetle
Location: SE Pennsylvania not far from Kennett Square.
May 16, 2014 10:03 pm
October 2013 in SE Pennsylvania not far from Kennett Square.
Signature: Joe Halloran

Oil Beetle
Oil Beetle

Hi Joe,
Congratulations on recognizing that this Oil Beetle in the genus Meloe is actually a beetle, as most requests we received confuse it for a large ant or other insect.  Oil Beetles do not resemble typical beetles as they do not have rigid elytra covering the body and protecting the flight wings.  Oil Beetles are soft bodied beetles with rudimentary elytra.

Letter 12 – Oil Beetle

 

Subject: Wondering what kind of ant is this
Location: Acworth, GA
February 9, 2015 12:15 pm
I found this large ant, assuming it is/was a queen, in my garden while weeding. I live in Acworth, GA and the ant was dead, but wanted to know what kind it is. It was about an inch in length and as far as I could tell completely black in color. Any ideas?? Thanks!
Signature: Gwen

Oil Beetle
Oil Beetle

Dear Gwen,
What you have mistaken for an Ant is actually an Oil Beetle in the genus
Meloe

Thank you!!!  Now I know not to touch a live one since they can cause blisters on human skin…always good to know!!
Love your site and appreciate all the information.
Gwen

Letter 13 – Oil Beetle

 

Subject: Mystery beetle or queen of the ants?
Location: Connecticut
September 26, 2015 4:32 pm
This bug was found crawling on the ground in our backyard in Connecticut. The front half looks very ant like but the abdomen was huge in proportion. It had little pronto wings but looked like it could not fly. We left it in a protected place to continue its journey after taking its photo.
Signature: Bug lover

Oil Beetle
Oil Beetle

Dear Bug lover,
This is an Oil Beetle in the genus
Meloe, one of the Blister Beetles.  Blister Beetles can secrete a compound known as cantharidin that can cause blistering in human skin, so Blister Beetles should be handled with caution, or not at all.

Letter 14 – Oil Beetle

 

Subject: Turquoise Bug
Location: Deep Creek, MD
October 5, 2015 9:02 am
No idea what kind of bug this is, but he sure is cool looking! Any ideas?
Signature: Drew N

Oil Beetle
Oil Beetle

Dear Drew,
This is a Blister Beetle in the genus Meloe, a group commonly called Oil Beetles.  According to BugGuide:  “the common name refers to the habit of exuding yellowish oily liquid from the joints when molested” and Blister Beetles are known for secreting a compound known as cantharidin that is known to cause blistering in human skin, but we are going to propose another origin for the name Oil Beetle.  Your own subject line calls this a turquoise bug, and these black beetles have a sheen that often reflects light back in different colors the same way that oil on the surface of water reflects light, and we believe that may the the origin of the common name Oil Beetle.

Letter 15 – Oil Beetle

 

Subject: American Oil Beetle?
Location: Hamilton Ontario
October 24, 2015 9:41 pm
Hello Bugman,
I’ve got another find for you! I think this is an American Oil Beetle, but it seems a good deal larger than the description I read. This guy was hanging out inside our museum for a day or two before I rescued him. He looked dull black indoors but once I got him out in the sunshine I could see he had a beautiful greenish sheen on him. Didn’t know what his preferred host plant was, so I hope he found something to eat! (& a warm place to hide!)
Signature: Alison

Oil Beetle
Oil Beetle

Dear Alison,
We don’t mean to alarm you, but you should exercise caution when handling any of the Blister Beetles in the family Meloidae as members of the family secrete a compound called cantharidin that is known to cause blistering in human skin.  Regarding Oil Beetles in the genus
Meloe, according to the University of Connecticut Home & Garden Education Center page:  “The adults feed on grass and  several leafy weeds and flowers. ”  Though The Smaller Majority site has a fascinating overview of the life cycle of the Oil Beetle, nothing is mentioned about adult food preferences.

Yikes! Thanks for letting me know. I’m glad she was in a good enough mood that no one got hurt! Will exercise caution in the future when handling unknown insects. Thank you for your time!
Alison Innes

Letter 16 – Oil Beetle

 

Subject: Weird Beetle
Location: Frederick, MD
November 27, 2015 8:44 am
I saw this bug when I took my dogs out. Was wondering if it was a threat to them!
Signature: Molly

Oil Beetle
Oil Beetle

Dear Molly,
This is an Oil Beetle in the genus
Meloe, a member of the Blister Beetle family.  Blister Beetles are capable of secreting a compound cantharidin that is known to cause blistering in human skin.  This Oil Beetle is not concerned with attacking or threatening your dogs, but if one of your dogs was to attempt to try to eat one, your dog might encounter some irritation or possibly even a more severe reaction.

Letter 17 – Oil Beetle

 

Subject: Gravid Queen Carpenter Ant?
Location: Wythe County, southwest VA, USA
December 7, 2015 9:36 pm
I’m not sure of the ID of this insect. I’m guessing it is a Carpenter Ant–a gravid queen–but I’m not sure. My son has been replacing a section of our roof here in southwest VA. He discovered this insect today on a rotten board that he had removed and had thrown to the ground. It was cold, so it was hardly moving, which made it easy to photograph. Thank you for any help in ID!
Signature: Carolyn

Oil Beetle
Oil Beetle

Dear Carolyn,
Many people mistake Oil Beetles, the flightless Blister Beetle in your image, for queen ants.

Thank you so very much!  This is the first time I’ve seen one!  Love your website!

Letter 18 – Oil Beetle

 

Subject: Looks like ants
Location: Huntsville, AL
December 12, 2015 8:43 am
We found this large ant-like bug inside the house near the back door. I thought it might be a queen due to its huge size (approx 25 mm). A few days later, however, we found another smaller one on the bathroom floor. I figured the odds of finding two queens was pretty slim, so now I’m stumped. I’m hoping they’re not carpenter ants, because they don’t seem to match any of the descriptions I’ve seen online.
Signature: Keith

Oil Beetle
Oil Beetle

Dear Keith,
This is not a queen Ant, though many of our readers mistake Oil Beetles for queen Ants.  Oil Beetles are Blister Beetles in the genus
Meloe, and they should not be handled as they secrete a compound cantharidin that may cause blistering in human skin.

Daniel,
Thanks for the info.  I was about to pick it up and toss it outside, because I thought it was just a ground beetle at first.  Once I got close to it and saw it wasn’t, I thought twice about picking it up.  I’m glad I didn’t!
Keith

Letter 19 – Oil Beetle

 

Subject: Is it a carpenter ant queen?
Location: Rhode Island
September 7, 2016 4:23 pm
What is this big big? My friend found it amongst her potatoes. I’m thinking carpenter ant queen but I’m not sure
Signature: Cindy

Oil Beetle
Oil Beetle

Dear Cindy,
This is a Blister Beetle in the genus
Meloe, commonly called an Oil Beetle.

Letter 20 – Oil Beetle

 

Subject: Shiny bluish anty thing?
Location: Maine
September 24, 2016 4:17 am
Found this crawling on the steps, probably about 1 1/2″ – 2″ long. It wasn’t moving very fast. The abdomen is very large, but in all other respects it looks ant-like to me. Do you recognize it?
Signature: Kai

Oil Beetle
Oil Beetle

Dear Kai,
This distinctive Blister Beetle is an Oil Beetle in the genus
Meloe.

Letter 21 – Oil Beetle

 

Subject: What’s this bug?
Location: New York /New Jersey USA
November 11, 2016 1:17 pm
This thing was huge. Do you know what it is?
Signature: Becky Lynn Ray

Oil Beetle
Oil Beetle

Dear Becky,
This is an awesome image of an Oil Beetle, a species of Blister Beetle in the genus
Meloe.

Letter 22 – Oil Beetle

 

Subject: Huge abdomen
Location: Springfield MO
January 24, 2017 9:30 pm
I just moved to springfield mo. It is winter here (January) I came across what resembled an ant or beetle. Unfortunately I could not obtain a clear photo for it was night time and my dog got to the bug before I could get it indoors to examine it. I am an avid hiker and i have done farm work, never have seen this before. There are several types of trees around the house but I could not identify the bug as a specfic beetle to the area.
Signature: Christopher

Oil Beetle

Dear Christopher,
Even with the poor quality of your image, the identity of this Oil Beetle is unmistakable.

Letter 23 – Oil Beetle

 

Subject: Darkling beetle?
Location: Silver spring, MD
March 8, 2017 8:01 pm
We found this one ob March 1st, a weirdly warm winter day here in MD and the closest thing to resemble it in our guide was a Darkling beetle. Is that what it was? It was very sluggish, we thought it was dead at first. My 6 year old wanted to pick it up but I didn’t know if it was safe. I kinda wish I had let her, just to get a more contrasting background.
Signature: Divya

Oil Beetle

Dear Divya,
This is not a Darkling Beetle.  It is a Blister Beetle, a member of a family that gets its common name because family members are able to secrete a compound, cantharidin, that is known to cause blistering in human skin.  The infamous aphrodesiac known as Spanish Fly is actually made of the ground bodies of a Spanish Blister Beetle.  Your individual is an Oil Beetle in the genus
Meloe and we believe it is a male because the fifth segment of the antennae appear to be modified for sexual interaction with the female.  Oil Beetles are found in many parts of the world.

Phew – I’m glad I didn’t let her pick it up! Thanks so much for letting us know; she loves bugs but is also sensitive enough that if any of them ever hurt her, she may fear them all. It is really odd that a chemical that can cause blistering could also be an aphrodisiac – maybe blistering your inhibitions? I loved the different textures of black color on this little bug.

Reader Emails

Over the years, our website, whatsthatbug.com has received hundreds of letters and some interesting images asking us about these insects. Scroll down to have a look at some of them.

Letter 1 – Oil Beetle

 

Subject: WTB
Location: Powder Springs, Ga
December 9, 2016 6:49 pm
Have no idea what this is. Found in Powder Springs, GA. My son and I admired it for a while then we let him go free.
Signature: Lataine III

Oil Beetle
Oil Beetle

Dear Lataine III,
This is an Oil Beetle, a species of Blister Beetle in the genus
Meloe.

Letter 2 – Oil Beetle

 

oil beetle
my boss [runs a tree-trimming, spraying etc company] found a bug … i’ve attached a photo – not the best photo = i took it. do you think it is an "oil beetle"? we are located in stockton new jersey, but do tree work in new jersey and pennsylvania, so is it possible that oil beetles are in our area?
thanks for your help?
lynnie

Hi Lynnie,
Yes, this is an Oil Beetle. They are also known as Short Winged Blister Beetles and are in the genus Meloe. They are found in your area. According to the Audubon Guide: “If disturbed, this beetle feigns death by falling on its side. Leg joints exude droplets of liquid that cause blisters.” We are hoping your photo shows this feigning death behavior and is not the result of extermination.

they did not exterminate it … they found it, and wanted to know what it was. they actually thought it was dead and brought it back to the shop. next morning it was moving. i had just put it out on the paper with the ruler to take the picture so mr beetle could just be faking it again. thanks for your help. i will share with my boss in the morning.

Letter 3 – Oil Beetle

 

queen ant?
Hi,
I saw this ant in NE Alabama just last week. We got a picture of it, but of course, it was so blurry you couldn’t even make out its shape. However, I ran across this photo someone had taken, and it is the same creature we saw. It was almost two inches long, most of which was abdomen. Is it for sure an ant and can you tell which one specifically? Thank you! And by the way, I love this website!
Best regards,
Mary Shew

Hi Mary,
It might look like an ant, but it is a Short Winged Blister Beetle or Oil Beetle, Meloe angusticollis.

Letter 4 – Oil Beetle

 

Subject: On my house
Location: Louisville ky
October 25, 2012 11:01 pm
Hey, this soft boddied insect with a large abdomen who was about 1.5 inches long was on my house. I tried to tap it off into a small box to move it into my yard, but it was fragile and I smashed it a bit. Very docile. Ideas?
Signature: Michael S

Oil Beetle

Hi Michael,
Your Oil Beetle is in the Blister Beetle family and it should be handled with caution.  Blister Beetles can exude a compound cantharidin that can cause blistering in human skin.

Thanks for the quick response.  Luckily I didn’t touch it directly, and though its abdomen smashed a bit and oozed some bright yellow, it seemed ok walking around in our yard.  I removed it into a small cardboard shipping box with the edge of an envelope.  My 3 year old was interested in touching it, as it was right by the front door of our house.  Thanks for identifying it.  I sent it to some local farmers who didn’t know what it was.
Thanks,
Michael S

Letter 5 – Oil Beetle

 

Subject: Invasion fo the giant WTHs
Location: SE Michigan
November 3, 2012 9:13 pm
Spotted four of these in my backyard in early November. Two pairs in widely-separated locations. About an inch long, black-green in color, big fat abdomens, small wings/wing covers. Very sluggish. What the heck are they?
Signature: Fred Robinson

Oil Beetle

Hi Fred,
This is an Oil Beetle, a type of Blister Beetle in the genus
Meloe.

Letter 6 – Oil Beetle

 

Subject: Blue Mud Wasp – Queen?
Location: West Virginia
September 23, 2013 9:06 am
Hi bugman,
This summer we’ve had these odd wasps on our pool house screen window, they didn’t seem to be aggressive at all. They were slightly metallic blue and their wings fluttered different from most wasps. They left just black spitted stuff on the window frame and they seem to be gone now. The bug in the photo was found just a few days ago and I’m wondering if she is their queen. She was about 30 yards from where the other ones were. I found her having a hard time climbing up the brick of our house. She/it didn’t seem to have wings & I didn’t see her fly at all. Any ideas?
It is nearly fall here in the lower lands of West Virginia.
Signature: Maria

Oil Beetle
Oil Beetle

Hi Maria,
Your insect is an Oil Beetle, one of the Blister Beetles in the genus Meloe.  People often mistake them for queen ants.  Blister Beetles should be handled with caution as they can exude a compound known as cantharadin that is known to cause blistering in human skin.

Hi Daniel,
Wow, glad I didn’t play with it! 😉  So I guess the wasps having the same metallic look is just a coincidence.  Thanks!
Maria

Letter 7 – Oil Beetle

 

Subject: What’s this black ant beetle bug?
Location: Peekskill, NY
October 11, 2013 4:24 am
What oh what is this curious bug? My daughter and I discovered it while heading out on a nature walk. It is the size of a quarter. I was on one side of its wooden perch and my daughter was on the other side. The bug slowly turned its head towards me, then my daughter, then back to me… It was creepy! Never seen this bug before and I’d like to know what it is.
Thank you!
Signature: Casey Nugent

Oil Beetle
Oil Beetle

Hi Casey,
This is an Oil Beetle in the genus Meloe, one of the Blister Beetles.  The modified antennae indicate that this is a male Oil Beetle, according to BugGuide.

Letter 8 – Oil Beetle

 

Subject: Large black beetle looking?
Location: Central New Jersey
October 22, 2013 5:25 am
I’ve seen this bug earlier in the year during summer i believe but just noticed them more and more. I think its the same bug that eats my dogs poop and lives in the ground. Gross! What is it?
Signature: Jimbo

Oil Beetle
Oil Beetle

Hi Jimbo,
This is an Oil Beetle, one of the Blister Beetles in the genus
Meloe.  To the best of our knowledge, they do not eat fecal matter.  We believe you are confusing it with a Dung Beetle.

Letter 9 – Oil Beetle

 

Subject: Large black bug
Location: Southern Ohio
November 7, 2013 8:16 pm
This was on the side of our house. I have lived here all my life and haven’t seen one. Any idea what it is?
Signature: Jennifer F.

Oil Beetle
Oil Beetle

Dear Jennifer,
We often get identification requests for Oil Beetles in the genus
Meloe from your part of the country at this time of the year.  Handle with caution.  Oil Beetles are Blister Beetles and they can exude a compound known as cantharidin which is known to cause blistering in human skin.  It is also the substance found in the aphrodisiac Spanish Fly.

Letter 10 – Oil Beetle

 

Subject: What IS this thing?!
Location: Memphis, TN
February 14, 2014 5:51 am
I found this crawling on the threshold of my front entrance tonight when I got home from work. I was shocked, because today was our first relatively warm (high above 40) day in about three weeks. So I brought her inside and had my son take some pictures. I thought maybe a queen ant, but figured you all could tell us for sure.
Signature: Editormum

Oil Beetle
Oil Beetle

Dear Editormum,
This impressive creature is an Oil Beetle, one of the Blister Beetles in the genus
Meloe, and you can see BugGuide for additional information.

Oil Beetle
Oil Beetle

Letter 11 – Oil Beetle

 

Subject: Beetle
Location: SE Pennsylvania not far from Kennett Square.
May 16, 2014 10:03 pm
October 2013 in SE Pennsylvania not far from Kennett Square.
Signature: Joe Halloran

Oil Beetle
Oil Beetle

Hi Joe,
Congratulations on recognizing that this Oil Beetle in the genus Meloe is actually a beetle, as most requests we received confuse it for a large ant or other insect.  Oil Beetles do not resemble typical beetles as they do not have rigid elytra covering the body and protecting the flight wings.  Oil Beetles are soft bodied beetles with rudimentary elytra.

Letter 12 – Oil Beetle

 

Subject: Wondering what kind of ant is this
Location: Acworth, GA
February 9, 2015 12:15 pm
I found this large ant, assuming it is/was a queen, in my garden while weeding. I live in Acworth, GA and the ant was dead, but wanted to know what kind it is. It was about an inch in length and as far as I could tell completely black in color. Any ideas?? Thanks!
Signature: Gwen

Oil Beetle
Oil Beetle

Dear Gwen,
What you have mistaken for an Ant is actually an Oil Beetle in the genus
Meloe

Thank you!!!  Now I know not to touch a live one since they can cause blisters on human skin…always good to know!!
Love your site and appreciate all the information.
Gwen

Letter 13 – Oil Beetle

 

Subject: Mystery beetle or queen of the ants?
Location: Connecticut
September 26, 2015 4:32 pm
This bug was found crawling on the ground in our backyard in Connecticut. The front half looks very ant like but the abdomen was huge in proportion. It had little pronto wings but looked like it could not fly. We left it in a protected place to continue its journey after taking its photo.
Signature: Bug lover

Oil Beetle
Oil Beetle

Dear Bug lover,
This is an Oil Beetle in the genus
Meloe, one of the Blister Beetles.  Blister Beetles can secrete a compound known as cantharidin that can cause blistering in human skin, so Blister Beetles should be handled with caution, or not at all.

Letter 14 – Oil Beetle

 

Subject: Turquoise Bug
Location: Deep Creek, MD
October 5, 2015 9:02 am
No idea what kind of bug this is, but he sure is cool looking! Any ideas?
Signature: Drew N

Oil Beetle
Oil Beetle

Dear Drew,
This is a Blister Beetle in the genus Meloe, a group commonly called Oil Beetles.  According to BugGuide:  “the common name refers to the habit of exuding yellowish oily liquid from the joints when molested” and Blister Beetles are known for secreting a compound known as cantharidin that is known to cause blistering in human skin, but we are going to propose another origin for the name Oil Beetle.  Your own subject line calls this a turquoise bug, and these black beetles have a sheen that often reflects light back in different colors the same way that oil on the surface of water reflects light, and we believe that may the the origin of the common name Oil Beetle.

Letter 15 – Oil Beetle

 

Subject: American Oil Beetle?
Location: Hamilton Ontario
October 24, 2015 9:41 pm
Hello Bugman,
I’ve got another find for you! I think this is an American Oil Beetle, but it seems a good deal larger than the description I read. This guy was hanging out inside our museum for a day or two before I rescued him. He looked dull black indoors but once I got him out in the sunshine I could see he had a beautiful greenish sheen on him. Didn’t know what his preferred host plant was, so I hope he found something to eat! (& a warm place to hide!)
Signature: Alison

Oil Beetle
Oil Beetle

Dear Alison,
We don’t mean to alarm you, but you should exercise caution when handling any of the Blister Beetles in the family Meloidae as members of the family secrete a compound called cantharidin that is known to cause blistering in human skin.  Regarding Oil Beetles in the genus
Meloe, according to the University of Connecticut Home & Garden Education Center page:  “The adults feed on grass and  several leafy weeds and flowers. ”  Though The Smaller Majority site has a fascinating overview of the life cycle of the Oil Beetle, nothing is mentioned about adult food preferences.

Yikes! Thanks for letting me know. I’m glad she was in a good enough mood that no one got hurt! Will exercise caution in the future when handling unknown insects. Thank you for your time!
Alison Innes

Letter 16 – Oil Beetle

 

Subject: Weird Beetle
Location: Frederick, MD
November 27, 2015 8:44 am
I saw this bug when I took my dogs out. Was wondering if it was a threat to them!
Signature: Molly

Oil Beetle
Oil Beetle

Dear Molly,
This is an Oil Beetle in the genus
Meloe, a member of the Blister Beetle family.  Blister Beetles are capable of secreting a compound cantharidin that is known to cause blistering in human skin.  This Oil Beetle is not concerned with attacking or threatening your dogs, but if one of your dogs was to attempt to try to eat one, your dog might encounter some irritation or possibly even a more severe reaction.

Letter 17 – Oil Beetle

 

Subject: Gravid Queen Carpenter Ant?
Location: Wythe County, southwest VA, USA
December 7, 2015 9:36 pm
I’m not sure of the ID of this insect. I’m guessing it is a Carpenter Ant–a gravid queen–but I’m not sure. My son has been replacing a section of our roof here in southwest VA. He discovered this insect today on a rotten board that he had removed and had thrown to the ground. It was cold, so it was hardly moving, which made it easy to photograph. Thank you for any help in ID!
Signature: Carolyn

Oil Beetle
Oil Beetle

Dear Carolyn,
Many people mistake Oil Beetles, the flightless Blister Beetle in your image, for queen ants.

Thank you so very much!  This is the first time I’ve seen one!  Love your website!

Letter 18 – Oil Beetle

 

Subject: Looks like ants
Location: Huntsville, AL
December 12, 2015 8:43 am
We found this large ant-like bug inside the house near the back door. I thought it might be a queen due to its huge size (approx 25 mm). A few days later, however, we found another smaller one on the bathroom floor. I figured the odds of finding two queens was pretty slim, so now I’m stumped. I’m hoping they’re not carpenter ants, because they don’t seem to match any of the descriptions I’ve seen online.
Signature: Keith

Oil Beetle
Oil Beetle

Dear Keith,
This is not a queen Ant, though many of our readers mistake Oil Beetles for queen Ants.  Oil Beetles are Blister Beetles in the genus
Meloe, and they should not be handled as they secrete a compound cantharidin that may cause blistering in human skin.

Daniel,
Thanks for the info.  I was about to pick it up and toss it outside, because I thought it was just a ground beetle at first.  Once I got close to it and saw it wasn’t, I thought twice about picking it up.  I’m glad I didn’t!
Keith

Letter 19 – Oil Beetle

 

Subject: Is it a carpenter ant queen?
Location: Rhode Island
September 7, 2016 4:23 pm
What is this big big? My friend found it amongst her potatoes. I’m thinking carpenter ant queen but I’m not sure
Signature: Cindy

Oil Beetle
Oil Beetle

Dear Cindy,
This is a Blister Beetle in the genus
Meloe, commonly called an Oil Beetle.

Letter 20 – Oil Beetle

 

Subject: Shiny bluish anty thing?
Location: Maine
September 24, 2016 4:17 am
Found this crawling on the steps, probably about 1 1/2″ – 2″ long. It wasn’t moving very fast. The abdomen is very large, but in all other respects it looks ant-like to me. Do you recognize it?
Signature: Kai

Oil Beetle
Oil Beetle

Dear Kai,
This distinctive Blister Beetle is an Oil Beetle in the genus
Meloe.

Letter 21 – Oil Beetle

 

Subject: What’s this bug?
Location: New York /New Jersey USA
November 11, 2016 1:17 pm
This thing was huge. Do you know what it is?
Signature: Becky Lynn Ray

Oil Beetle
Oil Beetle

Dear Becky,
This is an awesome image of an Oil Beetle, a species of Blister Beetle in the genus
Meloe.

Letter 22 – Oil Beetle

 

Subject: Huge abdomen
Location: Springfield MO
January 24, 2017 9:30 pm
I just moved to springfield mo. It is winter here (January) I came across what resembled an ant or beetle. Unfortunately I could not obtain a clear photo for it was night time and my dog got to the bug before I could get it indoors to examine it. I am an avid hiker and i have done farm work, never have seen this before. There are several types of trees around the house but I could not identify the bug as a specfic beetle to the area.
Signature: Christopher

Oil Beetle

Dear Christopher,
Even with the poor quality of your image, the identity of this Oil Beetle is unmistakable.

Letter 23 – Oil Beetle

 

Subject: Darkling beetle?
Location: Silver spring, MD
March 8, 2017 8:01 pm
We found this one ob March 1st, a weirdly warm winter day here in MD and the closest thing to resemble it in our guide was a Darkling beetle. Is that what it was? It was very sluggish, we thought it was dead at first. My 6 year old wanted to pick it up but I didn’t know if it was safe. I kinda wish I had let her, just to get a more contrasting background.
Signature: Divya

Oil Beetle

Dear Divya,
This is not a Darkling Beetle.  It is a Blister Beetle, a member of a family that gets its common name because family members are able to secrete a compound, cantharidin, that is known to cause blistering in human skin.  The infamous aphrodesiac known as Spanish Fly is actually made of the ground bodies of a Spanish Blister Beetle.  Your individual is an Oil Beetle in the genus
Meloe and we believe it is a male because the fifth segment of the antennae appear to be modified for sexual interaction with the female.  Oil Beetles are found in many parts of the world.

Phew – I’m glad I didn’t let her pick it up! Thanks so much for letting us know; she loves bugs but is also sensitive enough that if any of them ever hurt her, she may fear them all. It is really odd that a chemical that can cause blistering could also be an aphrodisiac – maybe blistering your inhibitions? I loved the different textures of black color on this little bug.

Reader Emails

Over the years, our website, whatsthatbug.com has received hundreds of letters and some interesting images asking us about these insects. Scroll down to have a look at some of them.

Reader Emails

Over the years, our website, whatsthatbug.com has received hundreds of letters and some interesting images asking us about these insects. Scroll down to have a look at some of them.

Reader Emails

Over the years, our website, whatsthatbug.com has received hundreds of letters and some interesting images asking us about these insects. Scroll down to have a look at some of them.

Reader Emails

Over the years, our website, whatsthatbug.com has received hundreds of letters and some interesting images asking us about these insects. Scroll down to have a look at some of them.

Authors

    by
  • Bugman

    Bugman aka Daniel Marlos has been identifying bugs since 1999. whatsthatbug.com is his passion project and it has helped millions of readers identify the bug that has been bugging them for over two decades. You can reach out to him through our Contact Page.

  • Piyushi Dhir

    Piyushi is a nature lover, blogger and traveler at heart. She lives in beautiful Canada with her family. Piyushi is an animal lover and loves to write about all creatures.

3 thoughts on “Beetle That Looks Like an Ant: Discovering Nature’s Master of Disguise”

  1. Just popped in to say that I spotted my first real live oil beetle last weekend! I was so darn excited. Glad you, Jimbo, have seen these zany beetles as well.

    Reply
  2. Molly,
    I just sent in a question about this beetle. Now I don’t have to wait for the answer I pretty much knew – it is not a good idea for my little dog to eat these bugs. I have them in my yard this year and have never seen them before. I live in Olney, MD, so not too far from Frederick.

    Is this a new resident in the state? Remember the invasion of the stink bugs several years ago? My little dog at those too.
    Briana

    Reply

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