University of Maryland Extension

Booklice

book lice

  • 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.

book lice nymph
Booklice adult and nymph

Rev. 2020

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