Book louse (or Booklice)
Scientific Name: Liposcelis spp. (often Liposcelis bostrychophila)
Order & Family: Order: Psocodea (formerly Psocoptera), Family: Liposcelididae
Size: Very small, typically 1 mm to 2 mm in length.
Natural Habitat
Found indoors in high-humidity areas, damp basements, windowsills, inside books, behind wallpaper, in stored dry foods (flour, grains), and outdoors under bark or in leaf litter.
Diet & Feeding
Feeds on microscopic molds, fungi, starch-based glues (like those used in bookbinding), grain products, pollen, and dead insect fragments.
Behavior Patterns
They do not bite or sting. They are wingless (often) and move in a quick, jerky, running motion. They thrive in humid environments and reproduce rapidly via parthenogenesis (asexual reproduction).
Risks & Benefits
Generally harmless to humans and pets as they do not transmit diseases. However, they can be a nuisance pest, contaminate stored food products, and their presence usually indicates a moisture or humidity problem in the home.
Identified on: 2/25/2026