The chicken body louse, Menacanthus stramineus (Nitzsch), can decrease egg production in caged layer hens. The skin of infested birds becomes irritated and red with formation of localized scabs and blood clots. In addition to feeding on skin fragments, feathers and debris, lice can attack young quill feathers feeding on blood. Although found naturally infected with the virus of eastern encephalomyelitis, it is not considered an important vector. Adult chicken lice are flat-bodied, yellowish colored, 1/16 inch long with chewing mouthparts.