- Booklice (psocids) are tiny insects. They are 1 to 2 millimeters long, and range in color from almost colorless, to gray or light brown.
- Booklice prefer damp, warm, undisturbed situations. They become most numerous in houses during spring and summer.
- Booklice mostly feed on mold spores, but may also feed on starchy materials. They usually cause no damage.
- The most effective way to control book lice is to reduce moisture and/or humidity.
![booklice nymph](/sites/extension.umd.edu/files/styles/optimized/public/2021-02/HGIC_insects_booklice_nymph_JD.jpg?itok=CrvYUWD4)
Booklice adult and nymph. Photo: John Davidson, University of Maryland
Rev. 2020