Types of Pseudoscorpions: Discovering the Miniature Arachnids

Pseudoscorpions are fascinating creatures belonging to the class Arachnida. These tiny arachnids, ranging from 2 to 8 millimeters in length, may not be widely recognized due to their secretive nature and small size. Despite their name and appearance, with their four pairs of legs and large pedipalps, they are quite distinct from true scorpions, as they lack the tail and stinger associated with their more fearsome relatives.

As you delve into the world of pseudoscorpions, you’ll discover various types adapted to different habitats. These fascinating arachnids can be found in places such as leaf litter, moss, under tree bark, stones, and even bird and mammal nests. Beneficial to the environment, pseudoscorpions feed on small insects and other arthropods, keeping their populations in check.

Basic Characteristics

Appearance

Pseudoscorpions are tiny arthropods that resemble scorpions but lack a long tail and stinger. They have a distinct body structure, including two main body parts: the cephalothorax and the opisthosoma. The cephalothorax is the front part of the body, which consists of the head and holds the eye and mouthparts. The opisthosoma is the abdomen housing the internal organs.

These creatures have eight legs and two large pincers, or pedipalps, which they use for capturing prey and mating. Pseudoscorpions vary in size, ranging from 2 to 8 millimeters. Their body is divided into multiple segments, making them more flexible. There are over 3,000 species from more than 430 genera.

Behavior

Pseudoscorpions exhibit unique behaviors, such as:

  • Predation: These tiny arachnids are predators that feed on small insects and mites.
  • Molting: Like other arthropods, pseudoscorpions molt multiple times throughout their life to grow.
  • Phoresy: Some pseudoscorpion species hitch rides on larger insects for transportation, a behavior known as phoresy.

In comparison to true scorpions, pseudoscorpions are much smaller and lack a venomous tail stinger. However, both have similar body structures such as cephalothorax, opisthosoma, and eight legs. They also share the same predatory behaviors, but pseudoscorpions are more likely to be found in leaf litter and under bark, whereas scorpions inhabit a broader range of habitats.

Feature comparison Pseudoscorpion Scorpion
Size 2-8 mm 9-21 cm
Body Parts Cephalothorax and Opisthosoma Cephalothorax and Opisthosoma
Legs 8 legs 8 legs
Venomous Stinger No Yes
Habitat Leaf litter, under bark Various habitats

By understanding the appearance and behaviors of pseudoscorpions, you’ll be able to better appreciate these small yet fascinating creatures!

Species and Genera

Common Types

Pseudoscorpions are tiny arachnids that come in many species and genera. Some common types include the house pseudoscorpion, also known as Chelifer cancroides, the garypus titanius, and the dracochela deprehendor. You may not see these creatures often, as they are small and secretive. Their size ranges from 1/16 to 1/8 inch long, and they are typically reddish-brown in color. Don’t worry, these little guys are harmless and even beneficial, as they feed on pests like mites and small flies.

Genera Distribution

There are several major pseudoscorpion families, such as Chernetidae, Chthoniidae, Neobisiidae, Cheliferidae, Cheiridiidae, Garypinidae, Atemnidae, Pseudochiridiidae, and Syarinidae. These families belong to two super-families: Chthonioidea and Cheliferoidea. Here’s a quick comparison of the two:

Super-family Key Characteristics
Chthonioidea Primitive mouthparts, without trichobothria
Cheliferoidea More advanced mouthparts, with trichobothria

The distribution and range of pseudoscorpions vary depending on their habitat and species. They can be found in diverse environments, including leaf litter, under bark, in soil, and even within our homes. The indoor-loving Chelifer cancroides, or house pseudoscorpion, is mostly found in Europe and North America.

To sum up, you can find different species and genera of pseudoscorpions spread worldwide. Their distribution is influenced by habitat, climate, and geographic location. Observing these intriguing arachnids can be a fascinating experience, and knowing their role in controlling pests makes them even more welcome guests.

Habitat and Niche

Usual Habitats

Pseudoscorpions can be found in various habitats, such as bark, leaf litter, stones, and soil. They also live in moist and dark places, like caves, tree bark, and tree hollows. Even the seashore and firewood can be home to these small arachnids. As they are tiny creatures, they often go unnoticed in their surroundings.

Role in Ecosystem

In the ecosystem, pseudoscorpions play a crucial role as predators. They feed on various small insects and arachnids, such as:

  • Booklice
  • Ants
  • Mites
  • Spiders
  • Ticks
  • Flies
  • Dust mites

By controlling the populations of these organisms

Diet and Feeding

Prey

Pseudoscorpions are predators that primarily feed on small arthropods. Their prey includes a variety of organisms such as:

  • Ants
  • Mites
  • Spiders
  • Flies
  • Ticks
  • Dust mites
  • Small flies

These tiny creatures are beneficial as they help control the population of pests in their environment, such as carpet beetles, ants, and mites.

Feeding Mechanism

The feeding mechanism of pseudoscorpions involves the use of their pedipalps, which are pincer-like claws. These pedipalps grasp and immobilize the prey before feeding. Some species also possess venom glands within their pedipalps to subdue their prey more effectively.

Pseudoscorpions have silk-producing glands that allow them to construct silk structures. They often use these structures to help capture their prey, similar to how a spider would use its web.

While they share some similarities with true scorpions, such as the presence of pincers, pseudoscorpions do not have a stinger on their tail, making them harmless to humans. To summarize, pseudoscorpions are efficient hunters that rely on their pedipalps and venom glands to catch and consume a variety of small arthropods, providing an essential service in maintaining a balanced ecosystem.

Reproduction

Mating

Pseudoscorpions have a unique mating process. The male will perform a mating dance to attract a female. Once the female is interested, the male deposits sperm into a structure called a spermatophore. The female then takes in the sperm from the spermatophore to fertilize her eggs.

After Mating

Once the eggs are fertilized, the mother will carry them in a special brood pouch on the underside of her body. She keeps her eggs and young safe inside this pouch until they go through several development stages

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 – Pseudoscorpion

 

Pseudoscorpion ID
Hi,
I have been wondering what this bug was for the longest time. I knew it couldn’t be an insect because it didn’t have six legs, and its claws were intrigueing. When I typed in "eight legs" "claws" and "insect" into Google, I came across your site with an immediate positive ID. Thanks!
Clarence

Hi Clarence,
Thank you for contributing a new photo of a Pseudoscorpion. We have had the same one on our homepage for a five months and it was time for a change.

Letter 2 – Pseudoscorpion

 

Subject:  Strange tiny insect with pincers
Geographic location of the bug:  Pittsburgh Pennsylvania
Date: 01/27/2018
Time: 05:48 PM EDT
Your letter to the bugman:  I just found this insect on my wall inside of my apartment. Have never see anything like it before.  It has 3 tiny legs on each side of the body plus the larger pincer on each side. Before killing it, the pincers were resting foreword, not pulled in like in the picture I took.  Any thoughts or ideas would be great!  Thank You so much.
How you want your letter signed:  My name is Lindsay… not sure what else to put there.

Pseudoscorpion

Dear Lindsay,
This is a harmless, predatory Pseudoscorpion that will help keep your home free of small unwanted creatures.  Pseudoscorpions seem to have adapted quite well to living with humans.  That is a conclusion we have reached after receiving 100s of identification requests of Pseudoscorpions found in homes.  We rarely, or possibly even never, receive images of Pseudoscorpions in natural environments.  Furthermore, most of our sightings are from colder climates, with the vast majority occurring in Canada.  Though you were unaware of its identity at the time of the killing, we hope in the future you will be more tolerant of Pseudoscorpions found in your home, so we are tagging this posting as Unnecessary Carnage.

Hi Daniel,
I really appreciate the speedy reply. Now that I know the insect is harmless I will definitely be tolerant of them, in the event I see another one.  I actually hate killing anything, including insects ( I actually put stink bugs outside instead of killing them, lol)
Thanks again
Lindsay

Letter 3 – Pseudoscorpion

 

Subject: Illinois, Chicago
Location: Chicago Illinois
April 24, 2015 1:18 pm
i found this on my bedroom wall. I’m scared.
Signature: k.

Pseudoscorpion
Pseudoscorpion

Dear K,
You have no reason to be scared of nor alarmed by this harmless Pseudoscorpion.

Letter 4 – Pseudoscorpion

 

Subject: Pseudoscorpion
Location: Munising Mi
March 10, 2017 3:54 pm
Hi. I found a Pseudoscorpion on my wall today. I was freaking out because it looks like a mutant tick. But my questions are..Is it normal to have one in my house during the winter? I live in the Upper Peninsula of Michigan.
Signature: NICOLE ROCHEFORT

Pseudoscorpion

Dear Nicole,
We would be hard pressed to state what is the preferred habitat of Pseudoscorpions, because most of our reports are of indoor sightings.  We can only deduce that Pseudoscorpions have adapted to cohabitation with humans in dwellings.

Letter 5 – Pseudoscorpion

 

Subject: Bug in Bed
Location: Southern Minnesota, USA
January 9, 2014 8:32 pm
Late last night, I found a bug in my bed. It made me nervous ask had never seen it before. It was found isolated and no others were found. It was a mahogany brown the size of a small seed. It had 6 small legs with two large “pinches” in the front. Do you know what it is?
Signature: Anne

Pseudoscorpion
Pseudoscorpion

Dear Anne,
Due to internet hysteria about Bed Bug infestations being on the rise, we understand that finding any bug in the bed might be cause for concern, however, this Pseudoscorpion will not cause you any problems.  These tiny predators will not bite people, but they will help to control other undesirable insects and other arthropods in the home, including young Cockroaches and quite possibly Bed Bugs as well.  Pseudoscorpions do not have venom, so they are perfectly harmless to humans.

Letter 6 – Pseudoscorpion

 

Tiny Scorpion
Thanks for the website. Now I know what this cute little creature is. Here is another picture to add to your marvelous collection. This one was about 3mm long and found in a backyard in Eastwood, NSW, Australia. The picture was taken with it crawling through the hairs on my arm.
Cheers,
Svend Petersen

Hi Svend,
Thank you for the excellent photo that really demonstrates the tiny scale of this marvelous Pseudoscorpion.

Letter 7 – Pseudoscorpion

 

Subject: Is this a tick?
Location: Central Alberta, Canada
April 10, 2016 12:49 am
Over the course of the past year I have found several of these in my home, and at my workplace. I have always found them crawling on walls, always very small (smaller than the size of a pin head). They squish very easily (I did not want the chance of anyone getting bitten if it was a tick) and do not move quickly. We do have a cat that goes in and out, and live in a heavily wooded area, so thought they could possibly be tick in a nymph or larvae stage coming in on the cat. As I have said, always found on walls, sometimes quite high up.
Signature: Kayla

Pseudoscorpion
Pseudoscorpion

Dear Kayla,
This is a harmless, beneficial Pseudoscorpion that will help keep your home and work free of other, potentially problematic pest species as it is a predator.

Letter 8 – Pseudoscorpion and Fly: Phoresy in Action

 

pseudoscorprion vs dipteran
June 22, 2010
I discovered these two guys going at on my bathroom counter while brushing my teeth. The fly kept taking off with the psuedoscorpion attached, but not getting very far and landing back on the counter. They did this a few times and every time they landed I took another photo. I never witnessed the endgame. My money’s on the fly ultimately escaping with 5 legs.
Tony
Greenwood IN

Phoresy with Pseudoscorpion and Fly

Hi Tony,
The first time we received an image of a Pseudoscorpion attached to the antennae of a Cerambycid Beetle, we were in awe at the ambitiousness of the tiny Pseudoscorpion’s hunting prowess, but Eric Eaton informed us that this was Phoresy in action.  Since then, we have received numerous Phoresy images.  Some creatures like Pseudoscorpions and Mites use other insects, especially winged ones, for transportation purposes.  We believe that is what is going on in this series of photos.  We will try to get an ID on your fly.

Phoresy: Pseudoscorpion attempts to fly with Fly

Letter 9 – Pseudoscorpion

 

Pseudoscorpion
Dear fellow,
I found that little "scorpion" in stored corn grain and take some photos for your collection.
Horia

Hi Horia,
What a detailed photograph you have sent our way. We wish you had provided a location for this interesting Pseudoscorpion specimen.

Hi,
Yes ideed is a pseudoscorpion, possible Pselaphochernes anachoreta. This specimen was found in a cereal grain storage, because this is a somekind of predator of other insect or mites. The specimen is mounted with Eukitt on slide. When is possible I’ll send you other interesting images with small insects.
Horia

Letter 10 – Pseudoscorpion

 

Wonderful Website helped me identify a creepy crawler
I just wanted to thank you for having such a great website with a lot of great pictures and information. I recently spotted an arachnid on my garbage can that had 2 large (relative to its tiny size, that is) pincers and I had no idea what it was. I live in the US Pacific Northwest, and I had posted my photo on a website asking for anyone to identify it – a friend directed me to your site, which identified it as a pseudoscorpion. I’m so glad to know what it is so I can learn more about this very intriguing critter. (I still think it looks kind of freaky though!) Here’s the photo I’d posted
Tiffany

Hi Tiffany,
Thank you for sending us your artful photo of a Pseudoscorpion. That green background sure is colorful.

Letter 11 – Pseudoscorpion

 

Please tell me!!!!!!!
Is it a deformed tick with claws? Is it some far off type of mite? Is it a miniature scorpion without a tail? What is it?!?!?!?!? I saw this creepy thing on my arm when I was outside! It is about 2 millimeters! I have no clue if this bug is harmful or harmless! Just tell me what this thing is!!!!!!!
Frances Yager

Hi Frances,
Fear not the harmless Pseudoscorpion.

Letter 12 – Pseudoscorpion

 

Subject: Eeeeek!
Location: San Diego, CA
July 5, 2013 11:38 am
So, saw this lone guy hanging out in plain view in my bathroom sink. Knew it was no ordinary house bug. It is the size of a flea but definitely not a flea – I took the picture under a microscope. It appears to be some sort of ectoparasite, but I can’t find any examples on the web of one with horns and long pincers. Help please?? Thank you!!
Signature: Kay

Pseudoscorpion
Pseudoscorpion

Hi Kay,
Fear not.  This is a harmless, beneficial, predatory Pseudoscorpion.

Letter 13 – Pseudoscorpion

 

Subject: arachnid?
Location: Sonoma County, California
February 9, 2014 5:32 pm
My wife found this little guy crawling around in the laundry room, waving the scorpion-like appendages. I took photos using a macro lens, which decided to focus on the ruler under the plastic measuring cup, so apologies for not having it exactly in focus. Neither of us has ever seen this particular insect before. At first she thought it may be a tick, but on further examination we are both stumped.
Signature: Larry

Pseudoscorpion
Pseudoscorpion

Hi Larry,
This is a harmless, predatory (beneficial) Pseudoscorpion, and you are correct that it is an arachnid.  Pseudoscorpions are harmless, because unlike their namesakes, they do not have venom.

Letter 14 – Pseudoscorpion

 

Subject: What’s this scorpion-like bug?
Location: Southeastern Vermont
October 12, 2015 5:43 pm
Dear Bugman,
I was helping my brother, Matt, install a window today, and after he pulled the insulation from between the studs and as I was taking a measurement he exclaimed, “whoa! a scorpion!” To which I anxiously responded, “really?!” Brother Matt, “well without the stinger.” Thankfully, I saw that is was quite small–barely the size of a dime. Reddish brown in hue and a zippy fast little thing–it was hard to get a still image. Clearly, this is not the infamous scorpion of desert regions, so what’s that bug?
Signature: Brother Brian

Pseudoscorpion
Pseudoscorpion

Dear Brother Brian,
This is a harmless, predatory Pseudoscorpion.  Interestingly, when we were formatting and renaming your image, we discovered we already had a Pseudoscorpion image submitted by a Brian in our archives.

Letter 15 – Pseudoscorpion

 

Subject: Creepy thing I found in my bAthroom
Location: Manitoba Canada
March 27, 2016 3:13 am
Found this bug in my seasonal home. Year or 2 back I found one filled with eggs, I thought I ended my battle with these creepy things. But they’re now back. My 3yo freaked out cause she found one in her potty. Now she won’t use a toilet unless it’s pristine cause “there’s spiders in it.”
Help.!
Signature: Elegantly

Pseudoscorpion
Pseudoscorpion

This is a harmless Pseudoscorpion.

K, but where are they coming from ? What do they survive on?

They come from a previous generation of Pseudoscorpions.  According to BugLife:  “Using a gland in their jaws pseudoscorpions can make disc shaped cocoons which can be used for mating, moulting or to provide shelter in cold weather. The males of some pseudoscorpion species use an elaborate mating dance by tapping their legs and abdomens to ensure that the eggs of the female become fertilised. The female will make a nest from silk and debris and will lay between 2 and 50 eggs into a brood pouch under her abdomen. Pseudoscorpions moult several times before they reach adulthood and once they reach this stage can live up to three years.”  They are predators that feed upon small insects and other Arachnids and they are considered beneficial.  More information can be found in our archives and on BugGuide.

Letter 16 – Pseudoscorpion

 

Subject: What is that??
Location: Alberta canada
June 30, 2016 11:38 pm
We found the bug in the bathroom and we are leaving in a apartment building having dogs and cats
Signature: English

Pseudoscorpion
Pseudoscorpion

Dear English,
This is a harmless, predatory Pseudoscorpion.

Letter 17 – Pseudoscorpion

 

Subject: what is this
Location: Nova Scotia Canada
December 14, 2016 11:51 am
hey just wondering what this is…found it in my house
Signature: mr.ennis

Pseudoscorpion
Pseudoscorpion

Dear Mr. Ennis,
This marvelous creature is a harmless, predatory Pseudoscorpion, a species that has adapted quite well to living in homes.

Letter 18 – Pseudoscorpion

 

Subject: What is this?!
Location: Michigan
January 22, 2017 5:11 am
Found this thing on the wall as got out of the shower!!
Signature: Aprile

Pseudoscorpion

Dear Aprile,
The harmless, predatory, beneficial Pseudoscorpion seems to have adapted to living indoors with humans where it preys upon other less desirable creatures in the home since almost all of the numerous images in our archives are interiors.

Letter 19 – Pseudoscorpion

 

Subject: Spiderscorpion
Location: Watersmeet, MI.
February 18, 2017 8:08 pm
Found this little creature crawling on the wall. I live in the upper peninsula of Michigan. We have been driven crazy by the government flies that were brought here 20 years ago to control the tent caterpillars and the Asian beetles that just won’t go home. What is this creature?
Signature: Grandma Mary

Pseudoscorpion

Dear Grandma Mary,
This is a harmless, predatory Pseudoscorpion, and they are often found inside homes.

Thank you for your time and knowledge.  No two look alike that I have seen.  But I have a lot of bugs for them and the spiders too.

Letter 20 – Pseudoscorpion

 

Subject: Bug identify please?
Location: Minnesota
May 5, 2017 3:52 pm
I found this bug on my pillow and freaked out. Haven’t slept in my bed since. The antenna are long and curve more than the photo suggest. U can kind of follow the curves where it blurs. I live in Minnesota and it’s warming up. May to be exact.
Signature: Sincerely cheri hennen

Pseudoscorpion

Dear Cheri,
This is a harmless Pseudoscorpion.  It poses no threat to you and it will eat other unwanted visitors in your home, like spider, bed bugs and small cockroaches.

Letter 21 – Pseudoscorpion

 

Subject: ID Please
Location: Sherman, CT
June 2, 2017 8:11 am
Please help us id this bug.
Is it a pseudoscorpion?
Signature: Beverly

Pseudoscorpion

Dear Beverly,
This is indeed a harmless, beneficial, predatory Pseudoscorpion.  We are postdating your submission to go live to our site later in the month when our editorial staff is on holiday.

Letter 22 – Pseudoscorpion

 

Subject:  Psuedoscorpion?
Geographic location of the bug:  Southern ontario
Date: 01/01/2018
Time: 03:57 PM EDT
I found this little guy in my bathroom, -20 °c lately I haven’t seen many bugs in a long time.
How you want your letter signed:  Mish

Pseudoscorpion

Dear Mish,
This is indeed a Pseudoscorpion, but it looks different from most of the individuals posted to our site.  According to BugGuide:  “They are not pests and are considered harmless.”

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 – wicked pincers

 

Hello,
I came across your site looking for info on this bug I’m seeing. We have a mite problem in this one room, where a bird nested in the eave, and I have laid down some double sided tape to try to determine where the entry point is, so I don’t have to RAID the whole room. Anyhow, a different bug has secured itself to the tape, almost making it across the span before apparently giving up in despair. It has pincers extending out like longhorn cattle horns, equal to the length of it’s body. I don’t have a camera at the ready, I’ll try to draw one and attach it, if you could be of any help. Greatly appreciated. I live in central Minnesota.
Thank you,
Steve

Hi Steve,
What a great drawing of a harmless Pseudoscorpion. We have an entire page with some photos. Just click the Pseudoscorpion link in the alphabatized list of the www.whatsthatbug.com homepage.

P.S. They may be eating your mites.

Daniel,
Thank you for the quick response and ID. I browsed your site for names I didn’t recognize, but I never thought to look at the pseudoscorpions. That’d be great if it was eating mites, except now I killed it with the tape trap.
Thanks again,
Steve

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.

4 thoughts on “Types of Pseudoscorpions: Discovering the Miniature Arachnids”

  1. June 21, 2018 I found a pseudo scorpion on my bathroom counter top in Rockford, Michigan. Took a picture with my camera.

    Reply
  2. “The antenna are long and curve more than the photo suggest.”
    The ‘antenna’ you speak of are actually claws like on a crab or a scorpion – hence the name pseudoscorpion. You’re very lucky to see one and also very lucky to have them around as they are great predators of pests like bedbugs and clothes moths. Apparently they’ve been around virtually unchanged for over 380 million years! I consider them friends!

    Reply

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