Ear mites are most commonly contracted from outside environments, or areas of poor hygiene and stress, such as pet stores and/or animal shelters.
Ear mites in dogs and ear mites in cats are tiny little creatures rather like spiders. They have eight legs and live on or just under the surface of the skin. The two species of mites that cause ear infections are Otodectes and Notoedres. Otodectes infect dogs, cats, foxes and ferrets. Notoedres infect cats—usually the body and sometimes the ear. A common mite that causes skin infection and may involve areas of the head around the ears is demodex. While demodex causes skin infections around the ear, it does not cause infections in the ear canal.
Ear mites usually infect young pets, especially pets in shelters, and abandoned puppies and kittens. Older pets are somewhat resistant to mites. If your pet's ear mites infect humans, the mite dies within a couple weeks because humans are not their natural host.