Booklouse (Barklouse)
Scientific Name: Liposcelis spp. (Common household genus)
Order & Family: Order: Psocoptera; Family: Liposcelididae
Size: Very small, usually 1 mm to 2 mm in length.
Natural Habitat
Typically found in damp, warm, and undisturbed areas indoors such as bookshelves, behind wallpaper, in cupboards, or stored food products. They thrive in humidity.
Diet & Feeding
They feed on microscopic mold and mildew, starch, book bindings, glue, and sometimes dried food grains.
Behavior Patterns
Booklice are flightless and move in quick, jerky spurts. They reproduce parthenogenetically (without males) in favorable conditions and can build up large populations quietly.
Risks & Benefits
They do not bite humans or pets and do not transmit disease. However, they are a nuisance pest that can contaminate stored dry foods and can indicate a moisture or mold problem in the home.
Identified on: 2/21/2026