Ear mites, Otodectes cynotis, are common parasites that live in the ear canal of cats. These microscopic white insectscan occur at any age but are more common in younger cats. The most common signs of ear mites are itching at the ear area and discharge of black exudate. Mites can also spread to the skin and when this happens cats will "itch" all over their backs, necks and tail areas.

Ear mites spend their entire life on the host. The female lays her eggs in the ear and in the surrounding fur. The eggs hatch after a four-day incubation period, and the larva feeds on ear wax and skin oils for about one week. It then molts into a "protonymph," which in turn molts into a "deutonymph." This deutonymph does not develop a gender until it mates with an adult male. If the result is a female, she will be laden with eggs.