Book Louse (Psocid)
book lice
Photo: Oregon State University
Size Up to 3/16 inch long
Where/when Found outdoors, on tree bark, plant foliage, or under stones. Found indoors in damp, warm, undisturbed places where mold and fungi are growing, especially during spring and summer.
Significance Nuisance. They are harmless to people and essentially harmless to property; on rare occasion, they can damage some paper products.