A pseudoscorpion, also known as a false scorpion or book scorpion, is an arachnidbelonging to the order Pseudoscorpiones, also known as Pseudoscorpionida or Chelonethida.
Pseudoscorpions are generally beneficial to humans since they prey on clothes moth larvae, carpet beetle larvae, booklice, ants, mites, and small flies. They are tiny and inoffensive, and are rarely seen due to their small size, despite being common in many environments. Pseudoscorpions often carry out phoresy, a form of commensalism in which one organism uses another for the purpose of transport.