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 indoors in high-humidity areas, damp basements, windowsills, bookshelves, behind wallpaper, and in stored food products.

Diet & Feeding

Feeds on microscopic molds, fungi, starch, glue (from book bindings), and sometimes stored grains.

Behavior Patterns

They do not bite or sting. They tend to run quickly in jerky movements rather than fly (this specific type is usually wingless). They thrive in humid environments where mold grows easily.

Risks & Benefits

Risks: They are a nuisance pest that can contaminate stored food and damage books by eating the starch in the bindings. Benefits: They do not transmit diseases to humans and act as an indicator of high humidity or mold issues in the home.

Identified on: 2/14/2026