Flea Anatomy

Fleas are insects, 2-8 mm long, and their body is divided into three parts: the head, thorax, and abdomen. Attached to the thorax are three pairs of legs for a total of six. They have no wings. The most noted flea characteristics are their medium brown to mahogany color and laterally flattened body. They are slightly smaller than a sesame seed. Now, back to their legs; the last pair is sufficiently enlarged, which equips them with a fantastic jumping ability.

Fleas have eyes and antennae, which detect heat, vibration, carbon dioxide, shadows, and changes in air currents, all of which indicate a possible meal is nearby.

Adult fleas, both male and female, feed on the blood of animals. They can go several months without a meal.

Flea Life Cycle

There are four stages in the development of fleas: eggs, larvae, pupae, and adults. Male and female fleas mate and two days later the female flea starts laying eggs. The eggs are often laid on the animal, but because they are not sticky, fall off into the environment. Along with the eggs, the female flea deposits a large amount of feces (often called 'flea dirt'). The feces, or flea dirt will dissolve into a red color when moistened; this is because it is primarily digested blood. The flea can lay 30-50 eggs in a day, generally in batches of 3 to 15, though she will not lay eggs every day. A flea can produce 400-1,000 eggs in her lifetime (several months to two years, depending on the species).

Two days (or more depending on temperature) after the egg is laid it hatches and the larva, which looks like a small maggot, starts to feed on the feces left by its mother. The larva passes through several phases of development taking a total of about a week. At that time, the larvae starts spinning a cocoon and is called a pupa. The cocoon is sticky and will often become covered with fine dirt or sand, and can be found deep in carpet or crevices. In a week, the pupa develops into an adult and emerges from the cocoon when it senses vibrations, carbon dioxide, or warmth, which tell it an animal host is near. The entire life cycle takes about 15 days, but the pupa can remain dormant under inhospitable conditions (e.g.; cold) and extend the cycle to over a year. This is important to remember when planning flea control.

What symptoms are caused by fleas and how is a flea infestation diagnosed?

Flea bites themselves may be unnoticeable on some pets, cause slight irritation in others, and produce severe itching, red lesions, hair loss, and even ulcers in a third group. The severe lesions are caused by a hypersensitivity to the flea saliva and is called flea allergy dermatitis.

Large numbers of fleas can cause anemia, especially in puppies and kittens. Some pets have been known to die if the anemia is severe.

The diagnosis of a flea infestation can be made by finding the adult fleas or 'flea dirt' (described above) on the animal. The best places to use a flea comb to detect fleas is around the hindquarters and head of the pet. These same areas should be examined for the 'flea dirt.'

Flea Control

Attempting to control fleas on our pets is a multi-step process. Adult fleas spend most of their time on an animal, but the flea eggs, larvae, and pupae are found in abundance in the environment such as in carpeting, rugs, bedding, and grass. For every flea that you see on your pet, there are likely to be hundreds of eggs and larvae in your home and yard. Therefore, a truly effective flea control program always includes treating the environment as well as treating your pet. These are the essential steps for a successful flea control program:

Flea Control for your pet

Program