Booklice (psocids)

Booklice, also called psocids, are not true lice. While they resemble lice in size and shape, booklice feed only on fungi or mould. If you find them it is an indication of high humidity which encourages mould 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.

 

The best way to control booklice is to eliminate moist environmental conditions. Insecticidal treatments can help but reducing the humidity in your building will greatly reduce the mould on which the booklice feed. Lowering the relative humidity to less than 50% will prevent their development in the future.

 

This can be done by increasing the ventilation when cooking, after a shower/bath, or when drying clothes. The installation of a good dehumidifier will also assist in reducing the background moisture.