Animated coloured scanning electron micrograph (SEM) of a common dog flea head (Ctenocephalides canis). This flea lives as an ectoparasite on a wide variety of mammals, in particular the domestic dog or cat. This flea serves as the intermediate host of the dog tapeworm (Dipylidium caninum). Although they feed on the blood of dogs and cats, they sometimes bite humans. They can live without food for several months. Females must have a blood meal before they can produce eggs. Dogs often get infested with fleas through contact with other animals or contact with fleas in the environment. The strong back legs of this insect enable it to jump from host to host or from the environment onto the host. The flea's bite can cause itching for the host but for a sensitive or flea-allergic animal, this itching can be quite severe and leads to hair loss, inflammation and secondary skin infections.