Cat fleas are small, dark brown to black insects whose bodies are hardened and look compressed when viewed from side to side. They do not fly, but have strong hind legs that they use to jump and their mouth parts are designed to pierce the skin of their host and suck blood. While not seen unless using a microscope or dissecting scope, adults have spines on and near the head. These are important characteristics that professionals use to identify various flea species. Adult cat fleas are about ¼ inch long and wingless. The adult is usually the stage most often seen by the property owner.
Cat flea eggs are oval-shaped and only about 1/50 inch in diameter. Larvae that hatch from the flea eggs are about 1/20 to 1/5 inch long and look like a very small grub. The pupal stage has a silken cocoon that is prepared by the larvae and looks like it has a sticky outer surface of dirt and debris attached to the pupal covering.
As one might expect, they are very difficult to see since the silk covering gives them a camouflaged appearance. The cat flea’s life cycle is one of complete metamorphosis: an egg stage, larval (grub) stage, pupal (cocoon) stage and adult stage. The cat flea’s life cycle usually lasts from about 1 to 2 ½ months and
depends on the temperature and humidity of their habitat. Cat flea larvae do not consume blood; rather, they feed on almost any kind of organic debris that is located where they dropped. However, their main source of nutrition is dried adult faecal matter (“flea dirt”) that is made up of undigested, dried blood that
falls from the host animal to areas where the larvae live.