Booklouse (or Psocid)

Scientific Name: Liposcelis spp.

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

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

Booklouse (or Psocid)

Natural Habitat

Found indoors in high-humidity areas like bathrooms, kitchens, and basements; often discovered in books, papers, stored grains, or near moldy plaster.

Diet & Feeding

Primarily feeds on microscopic mold and fungi, but will also consume starchy glues (in book bindings), wallpaper paste, and stored grain products.

Behavior Patterns

They are wingless, soft-bodied insects that run quickly when disturbed. They do not bite or fly. They thrive in damp environments where mold growth is present.

Risks & Benefits

Risks: Generally harmless to humans and pets (no biting or stinging), but can be a nuisance pest in large numbers and may contaminate stored food. Benefits: They serve as an indicator of excess moisture or mold issues in a home.

Identified on: 2/28/2026