Booklice acquired the name because, well, they are commonly found between old books. They basically feed on the paste used in the binding of books, photos and wallpaper. They are scavenging insects that feed on dry, starchy materials and do not bite humans or animals.
Many a time I have opened an old book from my bookshelf, anticipating an exciting read but would find the pages crawling with tiny booklice. This would vex almost anyone and they would be then checking their other books for booklice.
Booklice thrive in damp, dark, humid areas. Thus, you can look for them in dark basements or storerooms. You might want to invest in a magnifying glass to see them clearly.
If you find booklice on objects, take them outdoors to dry in the sun. Booklice are soft-bodied insects and will dry out quickly in the sun, killing them.
In places like storerooms or closed areas, open up all the windows to let sunlight in and let the room dry out. Use a dehumidifier or a fan if you have one which will remove the moisture in the area.
Household insecticides such as pyrethrins or allethrins can also be used on old, damp books and old mattresses. If booklice becomes out of control in your house the best option would be to contact a pest control company for the use of insecticides.