Knemidocoptes mutans, often referred to as the scaly leg mite (SLM), is a sarcoptid mite responsible for causing disease in chickens. The mites are spread through direct contact with infected birds. K. mutans have been found on several different breeds of domestic and wild birds.
K. mutans are microscopic mites which live under the scales of the legs and feet of the bird. They are pale gray, 8-legged mites with flat, round bodies. They have a life cycle of 10-14 days. These mites will spend their entire lives on the host, burrowing tunnels underneath the skin, reproducing, defecating, and feeding on the connective tissue.