The Pseudoscorpion (Order Pseudoscorpiones) is tan, reddish-brown, or dark brown and typically measures 1–8 mm (1/16 to 5/16 inch). Pseudoscorpions are tiny arachnids belonging to the order Pseudoscorpiones, with over 3,300 species worldwide and several found across Arizona. Despite their alarming appearance — a flattened body wit.

The Pseudoscorpion poses minimal to no danger to humans or pets. No risk to humans or pets. Cannot sting, does not bite humans, and causes no structural damage. Presence indicates a healthy micro-ecosystem or a minor moisture issue attracting their prey.

In Arizona, pseudoscorpions are most often encountered in the following situations: Tiny crab-like arachnid with prominent pincers but no tail. Found singly in bathrooms, basements, bookshelves, or under bark. Often discovered when moving stored boxes or books. Moves sideways or backward like a crab.

The Pseudoscorpion is most active during: Year-round; most active spring through fall. Arizona's warm desert climate can extend activity periods compared to other states, so year-round vigilance is recommended in the Phoenix metro and surrounding areas.

Reduce indoor humidity and moisture sources that attract their prey (mites, booklice). Seal cracks and gaps around windows, doors, and foundations to limit entry. Declutter stored paper, cardboard, and books where prey populations build up.

Treatment is rarely warranted — pseudoscorpions are beneficial and self-limiting. If populations are unwanted, address the underlying moisture or prey issue. Pest Control Bros can inspect and identify any arachnid found in your home to confirm identification and recommend the appropriate response.

Yes — like all scorpions, Pseudoscorpions fluoresce bright green under UV (blacklight) illumination. Scanning your yard, garage, and home perimeter with a UV flashlight after dark is one of the most effective ways to locate and monitor scorpion activity. Pest Control Bros recommends this technique as part of any scorpion management program.