WHAT IS A FLEA?

Flea, the common name for the order Siphonaptera, includes 2,500 species of small flightless insects that survive as external parasites of mammals and birds. Fleas live by consuming blood, or hematophagy, from their hosts. Adult fleas grow to about 3 mm (0.12 in) long, are usually brown, and have bodies that are “flattened” sideways or narrow, enabling them to move through their host’s fur or feathers. They lack wings, but have strong claws preventing them from being dislodged, mouthparts adapted for piercing skin and sucking blood, and hind legs extremely well adapted for jumping. They are able to leap a distance of some 50 times their body length, a feat second only to jumps made by another group of insects, the superfamily of froghoppers. Flea larvae are worm-like with no limbs; they have chewing mouthparts and feed on organic debris left on their host’s skin.

Global

Vector: Xenopsylla cheopis (Rat Flea)

The rat flea is a parasite of rodents, primarily of the genus Rattus, and is a primary vector for bubonic plague and murine typhus. This occurs when the flea has fed on an infected rodent and bites a human, although this flea can live on any warm-blooded mammal.

The flea’s body is about one tenth of an inch long (about 2.5 mm). Its body is constructed to make it easier to jump long distances. Its mouth has two functions: one for squirting saliva or partly digested blood into the bite, and one for sucking up blood from the host. This process mechanically transmits pathogens that may cause diseases it might carry. Fleas smell exhaled carbon dioxide from humans and animals and jump rapidly to the source to feed on the new host.

Ctenocephalides felis (Cat Flea)

The cat flea (scientific name Ctenocephalides felis) is an extremely common parasitic insect whose principal host is the domestic cat, although a high proportion of the fleas found on dogs also belong to this species.

The cat flea can also maintain its life cycle on other carnivores and on omnivores, but these are only chosen when more acceptable hosts become unavailable. Adult cat fleas do not willingly leave their hosts, and inter-animal transfer of adult fleas is rare except in animals that share sleeping quarters.

Cats can be infested with infected fleas that carry Bartonella bacteria. These bacteria can be transmitted from a cat to a person during a scratch.