Ornithonyssus sylviarum, otherwise known as the northern fowl mite, is a common ectoparasite of chicken flocks worldwide. They are a very small mite, ranging in size from 0.5-1 mm (0.02-0.04 in).
NFM permanently live their entire lives on their host, spending most of their time on the feathers, traveling to the skin surface to feed on blood. During heavy infestations, NFM can cause the chickens a great deal of stress, pain and blood loss (they can potentially lose 6% of their blood daily).
