Pseudoscorpions and real scorpions share many similarities, despite their differences in appearance. Both belong to the class Arachnida, making them close relatives of spiders, ticks, and mites.
Pseudoscorpions possess flattened, oval-shaped bodies with two visible pedipalps (pincers), and are typically reddish or brown in color. Though they lack a stinger or tail like their true scorpion counterparts, these small creatures still showcase fascinating features that make them unique to the world of arachnids.
Real scorpions, on the other hand, are more recognizable with their segmented bodies, pedipalps, and a venomous stinger at the end of a tail. While their appearances may differ, both pseudoscorpions and scorpions share the remarkable ability to adapt and survive in diverse environments all around the globe.
Pseudoscorpions and Scorpions Overview
Pseudoscorpions and scorpions both belong to the Arachnid family, just like spiders, ticks, and mites. Being part of this classification, they share similarities in their features, such as:
- Both having eight legs
- Two pedipalps (pincers) present in both species
- Exoskeletons covering their bodies
However, they also have key differences.
Some of the notable differences between pseudoscorpions and scorpions are:
- Size: Pseudoscorpions are much smaller, with the largest ones only reaching about ¼ inch long. In contrast, scorpions are generally larger.
- Body Shape: Pseudoscorpions have a flattened, teardrop- or pear-shaped body, while scorpions have a longer and segmented body.
- Tail: Scorpions have a long and flexible tail with a stinger at the end, which they use for self-defense and hunting. Pseudoscorpions lack this distinctive feature.
|Size||Up to ¼ inch long||Larger|
|Body Shape||Flattened, teardrop- or pear-shaped||Longer, segmented|
|Tail||Absent||Long, flexible, with stinger at the end|
To summarize, while pseudoscorpions and scorpions both fall under the arachnid classification, they still exhibit some key differences. Pseudoscorpions are often referred to as “false scorpions” due to their visual resemblance but lack of a stinging tail. These tiny arachnids are unique in their own way, while still maintaining some traits that connect them to their real scorpion relatives.
Size and Body Structure
- Smaller in size
- Body length about 1/5 inch long (around 3/8 inch when including pedipalps) 1
- Larger in size
- Varying body length, typically 2-4 inches (larger species can be 8 inches or more)
Pseudoscorpions have a flattened, oval, or teardrop-shaped body structure, while scorpions possess a more elongated and segmented body1. Both have an abdomen and a cephalothorax.
Limbs and Pincers
- 8 legs
- Pedipalps with pincers (chela)1
- 8 legs
- Pedipalps end in pincers (chela) too
Despite their differences in size, both pseudoscorpions and scorpions share the number of legs (8) and their use of pedipalps functioning as pincers2.
- Chelicerae (mouthparts) for venom injection3
- No stingers or tails
- Stinger at the end of a curved tail4
- Venom injected through a stinger
Eyes and Mouthparts
- Eyes can be present or absent3
- Chelicerae for biting and injecting venom
- Typically have multiple eyes2
- Chelicerae for feeding purposes only
|Size||Smaller (1/5 inch)||Larger (2-4 inches, more for larger species)|
|Pincers||Chela on pedipalps||Chela on pedipalps|
|Venom Apparatus||Chelicerae (bite)||Stinger on tail|
|Eyes||Presence varies||Usually multiple eyes|
Behavior and Ecology
Both pseudoscorpions and real scorpions can be found in various habitats. Pseudoscorpions often dwell in leaf litter, under tree bark, and indoors (UMN Extension). Scorpions, on the other hand, are commonly found in dry and desert conditions but can also adapt to forests and grasslands.
Feeding and Diet
Both arachnids have similar diets consisting mainly of small invertebrates:
- Pseudoscorpions: prey on mites, springtails, and booklice
- Scorpions: eat insects, spiders, and other scorpions
Predation involves using their pedipalps to capture and manipulate their prey, injecting venom through the pedipalps in the case of pseudoscorpions, or a tail stinger in the case of scorpions.
Predation and Survival Strategies
Pseudoscorpions and scorpions exhibit different survival tactics:
- Pseudoscorpions: employ phoresy, hitching rides on larger insects to disperse and find new habitats
- Scorpions: use their venom for self-defense against predators
Both arachnids rely on their camouflage for protection by blending into their environments.
Reproduction and Life Cycle
Reproduction in both pseudoscorpions and scorpions involves the transfer of a spermatophore from the male to the female. However, their life cycles differ:
- Pseudoscorpions: females carry eggs in a brood sac until the larvae emerge and go through molting stages
- Scorpions: females give live birth and carry their young on their backs until the first molt
Role in Ecosystem
Pseudoscorpions and scorpions play vital roles in their ecosystems by controlling populations of small invertebrates and insects. They also serve as food sources for larger predators.
Interesting Varieties and Examples
Pseudoscorpions are small, harmless arachnids that resemble scorpions but lack a long tail and stinger. They have a flattened, teardrop- or pear-shaped body, with a size ranging from 1/16 to 1/8 inches long 1. A notable example of a pseudoscorpion species is the Chelifer cancroides, which preys on small insects such as flies and mites. Just like any other pseudoscorpion, they are considered beneficial for controlling other pests in homes 5.
- Harmless to humans
- Small size
- Flattened, teardrop-shaped body
On the other hand, scorpions are venomous arachnids with a larger body size and a long tail equipped with a stinger. They belong to the same class as pseudoscorpions but are more aggressive and have a more diverse range of species. There are over 1,000 scorpion species in the world, with Mexico being home to the highest diversity of scorpions 3. A well-known example of a scorpion species is the Emperor Scorpion, which is a popular pet due to its imposing size and relatively mild venom.
- Larger body size
- Long tail with a stinger
|Size||1/16 to 1/8 inches long||Varies depending on the species|
|Body Shape||Flattened, teardrop- or pear-shaped||Segmented, elongated body|
|Tail with Stinger||No||Yes|
|Harmful to humans||No||Some species|
|Prey||Small pests such as flies and mites||Variety of insects and small animals|
Miscellaneous Related Topics
Aristotle and Micrographia
Aristotle was one of the first researchers to study pseudoscorpions and real scorpions, focusing on their similarities and differences. Micrographia, a science publication by Robert Hooke, also took interest in these arachnids, showcasing their unique characteristics.
Bugs That Look Like Scorpions
There are a few bugs that resemble scorpions, such as:
- Dust mites
- Land crabs
Though they may appear similar, they do not share the same harmful abilities or characteristics.
When Scorpions and Pseudoscorpions Meet Humans
Scorpions and pseudoscorpions can encounter humans in various situations, such as in:
- Tropical and subtropical regions
- Mulch or burrows
- Infestations in the UK
Both arachnids have the ability to pinch with their pedipalps, but only scorpions possess a venomous stinger to deliver toxins.
Comparison between Scorpions and Pseudoscorpions:
|Size||Larger (up to 20 cm)||Smaller (up to 5 mm)|
|Color||Varies, often black||Reddish or brown|
|Glands||Poison gland in stinger||Saliva glands, no poison gland|
|Habitat||Burrows, under rocks||Cocoons, leaf litter|
|Harm to humans||Can be harmful||Rarely, if ever, harmful|
Scorpions are generally more destructive than pseudoscorpions, but both are important in maintaining a balance in the ecosystem. For example, pseudoscorpions can control infestations of other pests like dust mites or help clean up detritus. Overall, interactions with humans are rare, but always practice caution when encountering any arachnid.
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
Small Bug with 2 long arms like lobster pinchers
Sat, Mar 21, 2009 at 5:07 AM
I found this bug twice in our bathroom and this morning in our kitchen. I was reading the paper and it might have crawled off my t shirt. Unable to identify it.
This is a harmless Pseudoscorpion, a minute predator often found indoors. We get countless identification requests from around the world on Pseudoscorpions, and we should probably include it in the Top Ten Tag. Though your photo is not the most detailed we have ever received, we love the inclusion of the ruler in the photo so our readership can see just how tiny this amazing predators really are.
Letter 2 – Pseudoscorpion
small tick-like insect with pinchers
October 21, 2009
I found it on my bedroom wall on 10/21/09.
Pseudoscorpions are harmless predators that are found worldwide. Because of their small size, they are rarely noticed except whey they are discovered inside homes.
Letter 3 – Pseudoscorpion
what kind of bug is this?
My Husband and I were wondering what this bug is. We saw it in a Vermont bed and breakfast bathroom crawling across the floor. It was only about 1/8” long (the picture shows it on a sheet of toilet paper to get an idea of how tiny it was). To us it looked like a cross between a scorpion and a tick but with no stinger. We looked at your web site but didn’t see anything like it.
Thanks for the information!
Sharon & David
Hi Sharon and David,
The harmless Pseudoscorpion probably helped to rid the bed and breakfast of problematic insects.
Letter 4 – Pseudoscorpion
Can you dentify this bug?
July 10, 2009
Can you dentify this bug?
Found in Bend, Oregon near kitchen window inside:(
I first thought it was a tick, but it has pinchers, and walks backward like a crab. It is dark reddish-brown with no spots or other markings(see photo). Can you help us identify it, and should we be concerned that it was in our house? Thanks,
Bend, Oregun USA
The harmless predatory Pseudoscorpion is often mistaken for a tick. There are numerous species and they are found throughout the world.
Letter 5 – Pseudoscorpion
Great website! Glad I found it because I was pretty concerned when I found what I at first thought to be a tick on my chest, only to realize it had pinchers after pulling it off. I found this one in Virginia, and thought I would share my pictures with you.
We get many letters regarding Pseudoscorpions, but few are accompanied by photos since Pseudoscorpions are so small. Note to readers: They are also harmless.
Letter 6 – Pseudoscorpion
Thought you might like this…
I live in south Texas . I saw this little guy hanging out on my wall and thought I’d take a picture and send it in. The funny thing is, I’m taking classes right now and just today we covered Class Arachnida in Biology II. Loe and behold I come home and have a pseudoscorpion right in my dining room! I’ve never seen one in person before today. Enjoy the picture!
My what a nice image. Thanks for sending it. Since many of our Pseudoscorpion images are blurry, yous is a great addition.
Letter 7 – Pseudoscorpion
You saved a life! A bugs life that is….
I live in the Northeast US and tonight I saw what I thought was a deer tick on my counter after just coming in from cutting the grass. My concern came from the prevalent Lyme disease in this region and my friends recent unfortunate diagnosis. Being a techie I trapped it and g00gled >"eight legs" claws< and low and below your site comes up first. I follow the link and *whamo* I see the bugger there in your photos. A pseudoscorpion! Glad it’s not 50 times bigger cause it would be an adventure to deal with… mean lookin bugger. Your statement that he eats other critters saved its life and got it a first class seat on a solo transport to my basement to wreak havoc on the other critters down there. Must be my critter week as yesterday I moved a 6 foot black snake to the woods behind my house?… I beleive your site and concept here is very benefitial to others, I want to thank you for your services. As a thank you I have provided photos of my bugger in its first and last – most likely – photogenic moment. Look close I believe it is smiling! :]
Happy we could be of service.
Letter 8 – Pseudoscorpion
what’s this bug!
Moved into an apartment in November 2004, its on the 2nd floor of an old house here in Toronto. I’ve now found two of the same small but disturbing bugs, which I’m having difficulty identifying. The first was found in a newspaper which was on the floor by a recently acquired 1970’s organ. The other between photo’s in a plastic box (crawled into?) which was again on the hard wood floor in the same room. They look like very small crabs. They are a brown/red colour, have 8 legs, and two very long arms with claws at its front. The body is about 3mm, while the span of the arms/claws seem to be about 10mm. When disturbed, they pull in the arm/claws, and legs looking like a small brown bit of dirt. Attached is a photo of the first one, dead. Tried to save it but it died within a few hours of finding it (had it outside, cold here in Toronto!). Any help would be great!
Your Pseudoscorpions are not only harmless, they are quite helpful as they will eagerly eat many household intruders that do damage. Despite their small size, they will even capture houseflies. Those claws are quite lethal for small insects and other arthropods.
Letter 9 – Pseudoscorpion
whats this bug?
My name is Shayla and i live in southeastern wisconsin. i found this tiny little creature crawling on my ceiling and i watched it for a couple of minutes and i put my fingure close to it and it moved from side to side like a crab and so i tried to make it fall onto a piece of paper so i could get a better look at it. it seems to have eight legs also. so i figured i would go online to see what i could find .. i was not able to find out what kind of bug it was but i took some pictures of it with my webcam … hopefully you will be able to help me out as in telling me what this bug is and a little about it?
You have a harmless (unless you are a small insect or spider), Pseudoscorpion. They are arachnids, related to both spiders and scorpions. They have a worldwide distribution and are often found in homes.
Letter 10 – Pseudoscorpion
Sat, Nov 22, 2008 at 12:57 PM
Found 11/22/08, Central Indiana (Lebanon,IN) ,USA, In bathroom sink, Early winter. Exterior Temperature 30 degrees F.
Ruler shown is in mm.
Reece, the Scorpion King
Central Indiana, USA
This is a harmless Pseudoscorpion. They are often found in homes and they have a nearly worldwide distribution.
Letter 11 – Pseudoscorpion
Arachnid, stingerless scorpion???
Tue, Apr 21, 2009 at 3:17 PM
found this creature on my kitchen counter. about 1/8 in. long and 1/16-1/8 in wide, a very tiny thing. this is the second one that we have EVER laid our eyes on. pictures are attached.
East Tennesse Region
This is a harmless Pseudoscorpion. Various species are found nearly worldwide, and they are often encountered in peoples homes where they do their best to dispatch unwanted insect and arthropod visitors.
Letter 12 – Pseudoscorpion
Strange, tiny solifugid(?) found under UST.
December 7, 2009
I work for an environmental company, decommissioning underground tanks.
I was in Detroit, Oregon taking soil samples and overseeing the private decom of a heating oil tank when I found this guy. He was about 7 feet underground, in an erosion void under the tank. The tank had fortunately not leaked, so he is quite alive. I think he is some kind of solifugid, although I couldn’t see any chelicera, and his forelegs end in pincers instead of adhesive pads. The blue object on which he rests is my gloved finger, making him less than a centimeter in length. I found him in early winter, so I assume he was hibernating so deep underground. I apologize for the fuzzy pictures, he was a very active little guy when he woke up.
Detroit OR, elev.1,590 ft // 7ft deep in loose rocky soil
This is actually a Pseudoscorpion, but it doesn’t look typically like most Pseudoscorpions that are sent to us. We found a matching specimen on BugGuide from Illinois, but the species is not identified. Pseudoscorpions lack venom and they are harmless, beneficial predators.
Letter 13 – Pseudoscorpion
Pseudoscorpion on Monitor
December 31, 2009
I thought you might enjoy this pseudoscorpion as much as I did. I usually have one or two of them in the bathroom, but this is the first time that one showed up on the computer monitor.
These critters certainly look creepy, but ever since I read up on them after discovering the first one in said bathroom, I do enjoy them a lot. They’re busy little things, always moving around with such industrious determination that I diligently avoid treating them with the derisive contempt I employ for the ever-present cluster flies. It’d be like insulting a German housewife – simply unacceptable! 🙂
Thanks for sending us your great photo of a harmless Pseudoscorpion. We are also joyed to hear about your tolerance in the home.
Letter 14 – Pseudoscorpion
Does my house have crabs?
January 19, 2010
Please tell me what this thing is….does my house have a case of the crabs? The bug is in my home year round and is mostly found on the walls in my den. The picture has 1 as big as I’ve ever seen them. They are present in the summer and in the winter.
Dear Mr. Madcow,
This is a Pseudoscorpion, a harmless predator that will help rid your home of unwanted insect visitors.
Letter 15 – Pseudoscorpion
Bug in the Bunk Bed
January 23, 2010
My parents have a 20 yr old oak bunk bed which seems to be hosting a weird bug. I had first found it on the wall next to the bed then we moved the bed into a different room and I found another one a month later on the bed sheet. After each find, I cleaned like crazy…and yes another month or so later I found this one…What is it??? I took the bed out of storage in a barn four years ago. I think I remember seeing one then too but dismissed it. But now, it’s driving me crazy and well I don’t want my kids to be sleeping in the cool bed their grandparents set up for them when they stay there in the summer…can you help?
Western Massachusetts, country home
This is a harmless Pseudoscorpion, a predator that will help keep unwanted insects from your home without presenting any threat to humans or pets, unless your pets are cockroaches or houseflies.
Thank you very much for taking the time to reply.
I’m am honestly amazed for both the speedy response and the actual bug itself.
Thank you again.