Psocids also called booklice

Psocids are common but harmless insects. Yellow, brown, white or grey in colour and only 1mm long, most of the species are wingless. They are usually found in dark humid places such as kitchen cupboards, bathrooms, on drying plaster in new houses and on old books and stored papers in libraries and archival storage areas, where they feed on microscopic moulds.
Biology: Psocids live for about 6 months, during which time the female can lay up to 100 eggs laid separately at a rate of 1-3 per day. The eggs then hatch in 1-2 weeks depending on the surrounding humidity.

It should be noted that complete riddance is often difficult. Thoroughly air and dry the infested area as this will prevent the development of the microscopic moulds that Psocids feed on. Clean the infested area with a dry cloth or by vacuuming. Where the infestation is extensive, a residual insecticide can be applied to the cracks and crevices of the affected area.