About fleas

What are fleas?

Fleas are small wingless bloodsucking insects. They are about 3 mm long and feeds mainly on blood of mammals or birds. Their colors normally varies from black to brown. There are many different flea species of various biology and habitats. However, when it comes to cats and dogs you will predominantly find the cat flea, scientifically known as Ctenocephalides felis. Facts about this particular flea are introduced below.

Ctenocephalides felis

A Female Cat Flea with Eggs

The Cat Flea

Fleas are very climate dependent, as the flea larva is thriving poorly in a cold or dry environment. Consequently, the appearance of fleas will be very seasonal in temperate climate zones whereas in warmer climate they will be present all year. Far north or south on the globe the flea may be completely absent. Their life cycle can normally be completed under indoor conditions. In warmer climate, however, flea reproduction may also take place in protected outdoor areas like covered kennels, outbuildings, cellars and under dense shrubs. Fleas found on dogs and cats during the birds’ nesting season may also be bird fleas. They are very active in this period and will often seek other hosts than the birds. Although bird fleas bite dogs and cats (and humans) they are not able to reproduce on their blood. As there is no next generation, bird flea problems are normally self-limiting and die out quite quickly.

The flea life cycle

The fleas go through four different life stages of egg, larva, pupa, and adult. The eggs, larvae, and pupae you will find in cracks and crevices or carpets in the rooms the pet normally frequents. At pupation the flea larva will produce a silk-like sticky cocoon. The cocoon will protect the developing flea (pupa) for a prolonged period under unfavourable conditions and is very resistant to chemical and mechanical treament. When triggered by changes in temperatures and carbondioxide the flea will leave the cocoon and guided by changes in light it will seek out a host, normally a dog or a cat, where it will stay for the rest of its life.

The development period from an egg to the adult flea depends primarily on the temperature and may be completed in as little as 14 days at 90°F/32°C or be prolonged up to 140 days at 55°F/13°C. On its host, the female flea is capable of producing more than 25 eggs a day. The eggs are not sticky, and they will fall off your dog or cat together with the flea feces.

Adult fleas feed on blood, which they are sucking from their host. The larvae, however, feed on organic debris such as dried flea feces which contains residues from the digested blood meal of adult fleas.

How can I tell if my pet has fleas? – click here.

The Flea Life cycle