Booklouse (or Psocid)

Scientific Name: Order Psocoptera (Liposcelis spp. is common indoors)

Order & Family: Order: Psocoptera

Size: Very small, typically 1 mm to 2 mm in length.

Booklouse (or Psocid)

Natural Habitat

Damp, humid environments like bathrooms, kitchens, basements, wall voids, and anywhere mold grows. Often found on books, paper, wallpaper, or stored grains.

Diet & Feeding

Microscopic molds, fungi, starch, glue (like book bindings), and dead organic matter.

Behavior Patterns

They do not bite or fly (many indoor species are wingless). They are fast-moving and seek out moisture. Populations can explode quickly if high humidity allows mold to grow.

Risks & Benefits

Risks: They are a nuisance pest that can contaminate stored food products and damage paper goods or books. They can trigger allergies in some people. Benefits: They do not bite humans or pets, carry diseases, or damage structural wood.

Identified on: 2/25/2026