Identification, Images, & Information
For Insects, Spiders & Their Kin
For the United States & Canada

Order Pseudoscorpiones - Pseudoscorpions

Pseudoscorpion Pseudoscorpion Pseudoscorpion - Apochthonius Pseudoscorpion - Chelifer cancroides Pseudoscorpion - Microbisium Pseudoscorpion
Kingdom Animalia (Animals)
Phylum Arthropoda (Arthropods)
Subphylum Chelicerata (Chelicerates)
Class Arachnida (Arachnids)
Order Pseudoscorpiones (Pseudoscorpions)
Other Common Names
false scorpions
Explanation of Names
"Pseudoscorpiones" is from the Latin word-element pseudo, derived from Greek pseudos (ψηυδος) "false" + Latin scorpiones, the nominative singular form of scorpio "scorpion".
US: ~420 spp., 110 genera, 20 families(1); Canada: 26 spp., 20 genera, 7 families recorded; about as many others likely to occur(2)
worldwide: ~3,530 spp. in >450 genera of 26 families(3)(4)
body usually <3 mm
small, flat, with pincer-like pedipalps (but no stinging "tail" as in true scorpions)
identification keys provided in(2)(4)
under bark and stones, in leaf litter, caves, and homes(5)
Most individuals have poison glands in their pincers which they use to subdue small insects.(6)
They are not pests and are considered harmless
Even though most individuals have venom glands, the animals are not large enough to hurt people(6)
Can run backwards with ease
Often hitchhike on beetles to disperse

I remember them being abundant in the chicken houses I was responsible for while growing up and I assume they must have been feeding on bird lice [Troy]
None are known to be parasitic but they feed on arthropods in bird and rodent nests. They are sometimes found on beetles or other large insects where they apparently feed on mites.(7)
They commonly hitch rides on beetles or other flying arthropods to travel.