Booklouse (or Psocid)

Scientific Name: Liposcelis spp. (Common genus)

Order & Family: Order: Psocodea (formerly Psocoptera), Family: Liposcelididae

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

Booklouse (or Psocid)

Natural Habitat

Found in damp, warm, and undisturbed areas indoors such as bookshelves, behind wallpaper, in cupboards, and in stored food products. Outdoors, they live on tree bark and leaves.

Diet & Feeding

They feed on microscopic mold and fungi, as well as starchy materials like book bindings, glue, wallpaper paste, and sometimes stored grains.

Behavior Patterns

Booklice are wingless (often) and move in quick, jerky spurts. They do not bite or sting. They thrive in high humidity environments which encourage the growth of the mold they eat.

Risks & Benefits

Risks: They are a nuisance pest that can contaminate stored food and damage delicate paper items or books over long periods. Benefits: They are harmless to humans and pets (no bites/disease), and their presence serves as an indicator of high humidity or mold issues in a home.

Identified on: 2/25/2026