What is a flea?

Fleas are small insects, about ¼ inch in length, laterally flattened, and brown to black or gray in color. They are wingless, and have long hind legs for jumping. Fleas have sucking mouthparts, and as adults, feed on the blood of mammals or birds. Many species are very annoying because of their bites, and a few act as vectors for disease. Some people and pets are known to develop allergic reactions to flea bites.

Fleas become pests when they get into our houses. Fleas in houses are usually linked with a pet or a visiting cat or dog. Cat fleas (Ctenocephalides felis), and dog fleas (Ctenocephalides canis) are the species most often found in houses. Wild animals have fleas also, and if such animals are living in the homes, fleas may become a problem. Flea problems often occur when the host animal had been absent for a period of time, such as when the family goes on vacation, taking or boarding the pet. Fleas may also be driven into the house during prolonged periods of wet weather.

Each species of flea has one or two kinds of animals it prefers, although when hungry, it will attack a wide variety of warm-blooded animals, sometimes including humans. Adult fleas live on the blood of the animals, and must have a blood meal to reproduce.

Cat and dog fleas periodically jump on and off the host. When the host is removed for a period of time, they are left without food. Hungry adult fleas often attack on the first warm-blooded animal that comes in the door, often biting people around the ankles. In addition, vibrations are known to promote emergence of new adults from pupae; walking across the floor may trigger emergence.

Source: University of Florida Extension Service