Ear mites are tiny parasites that look like tiny crabs that latch on the fur and skin of the dog's ear canal. These ear mites feed on the ear wax and oils of the dog's ear. Ear mites do not burrow into the skin and typically stay in the ear although they can be anywhere else on the dog as well. Cases of ear mites occur more in puppies than older dogs. Ear mites should be treated right away or they will transmit to other hosts rapidly.
Ear mites can infect dogs in various ways. Mostly, ear mites are passed from dog to dog; so if your dog is around other infected dogs they can be infected. They are vary contagious and can be caught easily. If your dog is playing with other dogs or even other animals affected by ear mites they can get infected as well. Bad hygiene can also lead to ear mites. Humans are immune to ear mites so you do not have to worry about being infected by your dog.
It is important to take your dog to the veterinarian right away if you assume something may be wrong and get a diagnosis.