Saturday, June 23, 2012

Interesting Animals: Pseudoscorpion

A pseudoscorpion (aka "false scorpion"), showing the pincher-like pedipalps that give the group its name
Pseudoscorpions are arachnids, placing them in the same group as spiders, scorpions, and ticks, mites, daddy-long-legs, many other eight-legged creatures. They are small with a maximum body length of eight millimeters. Like spiders, these arthropods have silk glands, though their glands are near their mouth rather than at the end of their abdomen. Though they are harmless and lack stingers, the "scorpion" part of their name comes from their large, pinching pedipalps much like those seen in scoprions. Pedipalps, or are basically an extra pair of legs used for various purposes in arachnids, including feeding, defense, and reproduction.

The majority of pseudoscoprion species are found in the tropics, but there are also those found in colder climes. Rarely, they can turn up inside of homes. They are most often found in humid areas, so if found in a house they will usually be seen in bathrooms or basements. Since these animals are harmless, if you find one in your home it's recommended you leave them be. However, the best way to get rid of them is to dry out the area they are found.

Pseudoscorpion phoresy on a fly
These creatures are one of several groups known to practice phoresy, which would be more commonly referred to as hitchhiking. Some species of pseudoscorpion will attach themselves to the bodies of other insects so that they can be transported from place to place. One of the few times I've actually seen a pseudoscorpion was when one fell out from under the wing of a captured beetle that it had been riding on. Phoresy is an interaction where one species gains benefit and the other is unharmed and thus is a form of commensalism.

Though there are about two thousand species of pseudoscorpion, they are apparently difficult to identify.

Sources are Penn State, University of Minnesota, Texas A&M, and Michigan State University. Images are from Wikimedia Commons under Creative Commons licenses: one, two.


  1. Funny, I actually saw one of these about two months ago. I had to to look it up; we have wind scorpions, but it was soooo tiny I knew it wasn't one of those.

    1. I was actually inspired to post this after seeing what I's pretty sure was a pseudoscorpion fall from a tree and land on the windshield of the car I was in at the time. Coming across animals that aren't so common a find is always fun for me.

  2. A hitchhiking fake scorpion. i kind of love it.

    i saw a super strange looking bug in my car recently, should have snapped a photo though it was so small it wouldn't have shown up. it was like a microscopic greyish colored mini scorpion but without pincher type claws in the front. and since i'm in the north east part of the US, I doubt it was scorpion at all.

    bugs are fascinating.

    1. I wonder what that could have been? If I had a picture I'd try to identify it, but I'm pretty clueless from your description. It doesn't help I'm not particularly good at identifying a lot of arthropods, lol.