Pulex felis Bouché, 1835 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.

[3] The cat flea belongs to the insect order Siphonaptera which in its adult stage is an obligatory hematophage.

Adults of both sexes range from 1–2 mm long and are usually a reddish-brown colour, although the abdomens of gravid females often swell with eggs causing them to appear banded in cream and dark brown.

Like all fleas, the cat flea is compressed laterally allowing it to slip between the sometimes dense hairs of its host just above the top layer of the skin, resulting in an extremely thin insect that may be difficult to observe even if the host's coat is pure white.

[7] 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.

Cat fleas are holometabolous (undergo complete metamorphosis) insects and therefore go through four life cycle stages of egg, larva, pupa, and imago (adult).

The larvae require adequate ambient moisture and warmth, and will die at temperatures near freezing.

[12] While in this developmental stage the larvae will feed on a variety of organic substances, but the most important dietary item for them is the crumbs of dried blood that continually fall like snow out of the haircoat of the host after it has been excreted by the adult fleas as fecal material.

Pupation depends heavily on temperature and moisture, and takes a week or more to complete, though a fully pupated adult can remain inside of its cocoon in a state of semi-dormancy (called the "pupal window") awaiting signs of the presence of a host.

Small animals with large infestations can lose enough bodily fluid to fleas feeding that dehydration may result.

Thorough vacuuming, washing linens in hot water, and treating all hosts in the immediate environment (the entire household, for example) is essential for successful eradication.

When administering insecticides to pets for flea treatment, it is critically important to finish the full dose to limit the spread of resistance.

In Australia, it is predicted that warming temperatures will drive the cat flea distribution south.