There are over 2,000 described species of fleas. The most common domestic flea is the cat flea, Ctenocephalides felis felis . The adult cat flea, unlike many other fleas, remains on the host.
Adults require a fresh blood meal in order to reproduce.
The dog flea, Ctenocephalides canis , appears similar to the cat flea, but is rarely found in the United States. Cat fleas are commonly found on both cats and dogs in North America, while dog fleas are found in Europe. The two species are distinguished by a slight morphological difference which is detectable only under high magnification. Although it exists worldwide, the cat flea is most commonly found in the United States, in and around homes with pets. The cat flea life cycle is one of complete metamorphosis, involving the stages of an egg, larva, pupa, and adult.