6 Simple Ways to Get Rid of Psocids or Book Lice

Illustration on how to get rid of psocids

The Spruce

Psocids (Psocoptera), or booklice, are commonly found in new houses and other damp spots. The environment of new construction is relatively humid, and these teeny bugs thrive in moist conditions. Luckily, these bugs can be easily managed.

What are Booklice?

Booklice are not technically lice, though they resemble lice in appearance since both bugs are flat and grayish brown. Booklice are tiny, harmless insects that like to feed on fungi and mold.

Booklice usually ride into new homes on construction materials while the house is being built, and they stay on. They can also take up residence under wallpaper, in older books and papers stored in damp conditions, as well as in wet areas outdoors. Booklice feed on microscopic mold that grows where there's humidity. Typically the bugs will not survive when humidity levels drop. Although these bugs don't bite, sting, or bother people or pets, they can be slightly annoying. If you have a psocid problem, read on for tips on how to prevent or control booklice.


Click Play to Learn How to Get Rid of Book Lice

Psocid presence is actually the most common pest question that comes from people who have just moved into a new house. Although the tiny bugs can be an annoyance, they really are no more than that and eventually, the humidity in the new house will drop and these small insects will not survive. So, you really don't need to do anything besides living in the house.

But if they don’t die off soon enough on their own, you can reduce the humidity more quickly by opening windows, and using fans or dehumidifiers in the rooms that have the problem. Within about one to three weeks, the low humidity will kill the psocids and also help reduce the growth of the molds on which they survive.

Psocid/Book Lice Control

New houses are not the only places that have problems with psocids, however. The tiny bugs can live outdoors on bark feeding on mosses and lichens and in grass, leaves and damp wood.

Because they are so tiny, it’s impractical to try to prevent their entry into the home (beyond standard exclusion practices that can help keep out pests of all kinds), so it’s important to make your home as unattractive to these tiny bugs as possible. That is primarily by reducing or eliminating the moisture in which they thrive and the micro-molds on which they feed.

To prevent or control a psocid problem, you can:

  1. Reduce their food supply by cleaning with enzymes and/or borax, then keeping the areas clean and free of molds and mildew.
  2. Use a dehumidifier or air conditioner in the infested or potentially infestation areas to reduce moisture to below 50 percent. Using fans can also help to increase the air flow.
  3. Dispose of all moldy articles.
  4. Reducing the temperature to below freezing for one hour can also kill off the psocids, but this would be impractical for a home, though it could be viable for infested items … particularly for those who live in the Northern climates where an article could be placed outdoors when the temperatures drop below freezing.
  5. Silica aerogel, diatomaceous earth or boric acid can be dusted in non-food area cracks and crevices, crawl spaces and other areas away from children and pets, to help dry out the area.
  6. Commercial products that help to control mold and fungi will also help keep the areas clean and maintain control of mold-feeding pests.

Additional information provided by Bill Robinson's The Service Technician's Field Manual and Stephen Tvedten's The Best Control 2.

Article Sources
The Spruce uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. Booklice. Penn State Extension, 2017.

  2. Drees, Bastiaan M. Booklice. Texas A&M AgriLife Extension Entomology.