Like mosquitoes and bed bugs, fleas subsist by consuming the blood of their hosts. While various types of fleas seem to prefer particular animal species upon which to prey, cats, rabbits, squirrels, ferrets, rats, mice, birds and, of course, humans are all would-be targets.
Flea bites create elevated, bloated spots (often with a puncture spot at their center) and often grow in groups, or lines, of two or three bites, which can sometimes remain irritated for weeks at a time.
Adult fleas are normally about 0.12 inches long and are dark reddish-brown in color. Even though fleas lack wings, they do have large hind legs, which help them jump up to 50 times their body length. They are also somewhat flat in shape, which permits them to move effortlessly among the fur, hair or feathers of the host.
Keep in mind that adult fleas can cause a variety of medical problems, including flea allergy dermatitis, the transmission of tapeworms, secondary skin irritations and, in rare instances, anemia.