Booklice infests a wide range of grains, commodities and storage facilities. Booklice, also called psocids, are not true lice. While they resemble lice in size and shape, booklice feed only on fungi or mold. If you find them in grain or other stored food products, it is an indication of high humidity which encourages mold growth. In addition to food products, psocids may be found under wallpaper, in furniture, along the sides of windows or on window sills around potted plants. Booklice do not bite, transmit disease, or damage food or fabric, but they can be very annoying when present in large numbers. Booklice feed on molds and will overrun cereals and similar materials that support mold growth. Their presence, therefore, is a nuisance and can render some foods unfit. The starchy paste of wallpaper and books also can support mold growth or may be attacked directly by booklice. Outside of annoyance, their damage is insignificant.
They are very small, soft-bodied. Adult varies in size according to species from 1/16"" - 1/8"" long and they are pale yellow–brown to dark brown in color. Nymphs are very small, often appear transparent. No larval stages.
They prefer high temperatures 77-86°F. Lepinotus patruelis — will breed at 40-60°F.
It is common in homes. A secondary pest, feeding on damaged grain and moulds. Warm and humid conditions increase their activity. It is usually observed in storage. It is simple to detect when they are low in numbers. They are common in factories and on pallets.