In build, the American Hairless Terrier is identical to the medium-sized Rat Terriers, from whom he is directly descended. The American Hairless is a well-muscled dog with a deep chest, strong shoulders, solid neck, and powerful legs. The ears are carried erect when the dog is alert and are called bat, similar to the Rat Terrier's. Tails must be full length. Bobs, either natural or docked are a disqualification. The skin is pink with gray, black, golden or red spots. Hairless-to-hairless breeding always produces completely hairless puppies. Hairless-to-coated mating is producing variable results, depending on chances and whether the coated dog is a carrier of the hairless trait. Hairless pups are born with a bit of sparse fuzzy hair all over their body. The pup will shed this fuzz, starting with the head, proceeding backwards, becoming entirely and eternally hairless by the age of six weeks. They do not have tufts of hair on the head, feet and end of tail, as do the Chinese Crested. They do however, have normal eyebrows and whiskers.