There are more than 100 species in the United States, with only a few that are found indoors. As the name suggests, Booklice feed on mold and the starches found in the paste and glues of book bindings and wallpaper, and when in numbers can do serious damage to books.
Booklice prefer damp, warm areas both outdoors and in, seeking spaces where mold is growing. They are colorless to gray to light brown and measure from 1/25 to 1/12 inch long. A single Booklice female will produce up to about 450 offspring. The average life span of a Booklice ranges from 25 to 110 days.
The Latin name of the Booklice order, Psocoptera, means “small rub” (psoco) and “winged” (-ptera), terms that refer to the abrasion-like damage caused by their feeding and the fact that some have wings. (Factoid Source: msn encarta)