These fast moving, minute, cream-coloured
or light brown insects, only 1mm long, occur
in small numbers in many premises. There
are several species, known collectively
as Psocides. All have soft bodies. Very
few species have wings. They are not related
to the parasitic lice. Sticky, pearl-coloured
eggs are cemented to damp surfaces and,
instead of a larval stage, the insect matures
through four recognisable nymphal stages,
taking about a fortnight in total. The adult
booklice are believed to feed on microscopic
moulds that grow on the glue of book-bindings
or on damp cardboard, damp food (especially
cereals) or on the surfaces of plaster,
leather or wood inside buildings. They can
occur in huge numbers in new properties
where the plaster is still damp. One species
of booklouse produces an audible tapping
noise by banging its abdomen against paper
or wood.
