Bark louse is a small, wingless insect commonly found on trees and shrubs. It is also known by various other names such as bark bug, tree louse, and psocid. Some people refer to it as booklice, although this term is more commonly used for other types of insects. Bark lice typically feed on fungi, algae, and other insects on the bark of trees and shrubs. They do not harm plants or humans and are considered beneficial to gardens and forests. Although often mistaken for lice, they are not parasitic and do not bite. Bark lice may have different names in different regions, but their characteristics and behavior remain the same.