What are Fleas?
Fleas are tiny, wingless, parasitic insects that feed on a wide variety of warm-blooded animals, including humans. Fleas have laterally flattened bodies (in other words, they're taller than they are wide), and are about the size of a pin head, on average. They have specially-adapted, piercing-sucking mouthparts with which they puncture the skin of their hosts. Most flea species are named after their preferred host, such as dog fleas, cat fleas, human fleas, and so forth. But if their preferred host isn't available, fleas will simply infest another animal instead. Pretty much any warm-blooded animal will do in a pinch if a flea gets hungry enough. Adult fleas have well-developed legs and can jump quite high. They use this ability to jump onto a host animal's body after having fallen or having been shaken off the body of another host. In fact, fleas spend quite a bit of their time jumping onto and falling off of their hosts, which is one way they spread through homes. Fleas hitchhike on pets (and sometimes humans), and get transported throughout the house.