Fleas: Siphonaptera

Free-living larvae scavenge scabs, flakes of skin, dried blood produced as waste by adult fleas, and other bits of tissue found in the host's nest. Some larvae live on the body of an animal, where they eat bits of skin and other tissues and fluids. Uropsylla tasmanica is the only larva known to burrow into the skin of its host, the Tasmanian devil. A few species prey on other insects that live in the host nest.

Adult fleas feed on host blood. Some species suck blood directly from a capillary (KAH-peh-LEH-ree), a small blood vessel just under the skin that connects arteries and veins. Others simply cut into the capillary and suck up the blood that pools on the surface of the skin. Males and females require a blood meal to produce sperm and eggs. Females usually drink more blood than males.