Booklice are found in moist, dark places and usually feed on decaying vegetation. They are so small that – unless you are looking for them – you would not notice them in nature. Unfortunately, they have also found human dwellings to their liking. In a home they are usually found where books are kept, i.e. the library or bookshelf. In libraries booklice can become a major problem as they feed on the starch and glue in book bindings. They will also feed on plant specimens (cellulose) and insects, so can be a problem in dry flower arrangements, herbaria and insect museums. My reference material indicates that booklice are “especially abundant in California.”
Control of booklice will be an ongoing process. Thoroughly vacuum the area where you find booklice. Repeat the thorough cleaning periodically. Check for moisture and make sure the infested area is as dry as possible. Infested books should be fumigated periodically as needed to disinfect them. Shelves can be sprayed with a household insecticide to destroy residual populations.