More Urban Species: House Pseudoscorpion

[urbpan]

House Pseudoscorpion  Chelifer cancroides

My apologies for the blurry photo.  The animal pictured has a body length of about three millimeters, and the camera I used was at its limit for macro photography.  Pseudoscorpions are tiny predatory arachnids, resembling scorpions but differing in having no stinging tail.  Instead they have venom glands in their pincers; these are much too small and weak to hurt humans or cats. 

The pseudoscorpion most often found inside houses and other buildings is Chelifer cancroides the house pseudoscorpion or book pseudoscorpion (or "book scorpion").  They prey on other domestic arthropods, including booklice, and may be found in old paper goods pursuing these creatures.  The house pseudoscorpion is found all around the world in the great indoors.  Some 400 other species are found in a variety of habitats, including one that startled the heck out of my brother and I as we camped in the Utah desert.  "Hey look a scorpion," is never a comforting thing to say to a fellow camper.  But when it turns out to be a harmless pseudoscorpion, that's okay.

Edited to add: Alexis took a really nice picture of one back in March:


Further reading and looking:
Penn State Entomology dept. page on this animal
Much better pictures than mine, from bugguide.net

Comments

Re: pseudoscorpions

[urbpan.livejournal.com]

No, they would only be a danger to a pet mite or springtail.