Booklouse (or Psocid)

Scientific Name: Liposcelis spp. (Common household genus)

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

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

Booklouse (or Psocid)

Natural Habitat

Found in high-humidity indoor environments, often near books, papers, wallpaper, or stored grains. They thrive in damp basements, windowsills, and areas with mold growth.

Diet & Feeding

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

Behavior Patterns

Booklice do not bite or fly (most household species are wingless). They run quickly in a jerky manner when disturbed. They require high moisture levels to survive and reproduce.

Risks & Benefits

Risks: They are nuisance pests that can contaminate stored food products and damage books or paper goods in large numbers. Benefits: They are harmless to humans (do not bite or spread disease) and their presence can be an early indicator of moisture issues or mold growth in a home.

Identified on: 2/25/2026