Fleas are external parasites; the adults can be found crawling on the skin of their hosts. Adult fleas measure approximately 2.5 mm in length. Their bodies are shiny and reddish brown in color. They are covered with microscopic hair and are compressed to allow for easy movement through animal fur. Fleas do not have wings, although they are capable of jumping long distances. They have three sets of elongated legs. Read more about what fleas look like.
Fleas commonly prefer to feed on hairy animals such as dogs, cats, rabbits, rats, mice and other domesticated or wild animals. Humans are not a preferred food source, and it is unlikely to have a sustained populations feeding only on humans.
The female flea lays her eggs on the surface hair of the host or on the ground. Eggs then drop from the host and can infest carpets, bedding and furniture, hatching into larvae within 12 days. Flea larvae avoid light and feed on organic matter found within cracks and crevices. Usually within 18 days, larvae enter the pupal stage by constructing small, cocoonlike structures around themselves. Approximately two weeks later, adult fleas emerge and begin to search for food sources. Fleas establish large populations where pets and other animals, such as livestock, are present. Multiple treatment methods are often employed to eradicate a flea population.
Pets suffering from flea bites scratch themselves incessantly. Fleas also feed on humans, and some people exhibit flea allergies. Fleas may also carry human diseases such as typhus and tularemia.
Appearance
Adults small, wingless, about 2.5 mm long. Covered in tiny spines with piercing mouthparts.
Behavior, Diet & Habits
Adults are parasites that draw blood from a host.
Larvae feed on organic debris, particularly the feces of adult fleas, which contain undigested blood.