Fleas are small wingless insects classified under the order Siphonaptera. They are external parasites, feeding off the blood of mammals and birds. They are very small, usually ranging from 1.5 to 3.3mm in length, agile, and are usually dark colored. Their mouths are tube-like, adapted to feeding on their host's blood. Fleas' bodies are flattened side to side, allowing them to move easily through the hairs or feathers on their host's body. Aside from this, their bodies are hard, polished, and covered with many hairs and short spines that are directed backward, assisting in movement. They can also withstand great pressure --- you normally can't kill a flea by squeezing them between your fingers. Their legs are long and are well adapted to jumping. A flea can jump for as high as 18 centimeters, and can cover a distance of 33 centimeters. There are four stages in the life cycle of a flea, although the life cycle depends on the species of the flea. Development from an egg to adult is normally two to three weeks, but when conditions do not favor the normal development, the cycle may take up to several months.

1. The Egg Stage. Female fleas usually lay about 20 or so eggs. The eggs are round, smooth, and light colored.
2. Larval Stage. During the larval stage, the eggs hatch into small, hairy wormlike larvae that are an off-white color, with darker heads. They are about 1.5 mm in length, although some can grow to five millimeters. Larvae are sensitive to light as well as changes in temperature. They mainly feed on organic debris: their own cast-off skins and on dried blood that are present in the excrement of adult fleas. They are resilient, able to survive 200 days in harsh conditions. They can also travel up to 30 cm per minute.
3. Pupal Stage. The pupal stage is the third stage in the development of fleas. Using particles of dust, organic debris, and fibers, the larvae spin silken cocoons around themselves. Inside this cocoon, they metamorphose into the adult fleas. At the onset, they are white, but they become brown before they emerge.
4. Adult Stage. When they become adults, the fleas turn into dark or reddish brown whose size ranges from one to four mm. They become the familiar shape of fleas you see in books and the microscope --- laterally flattened, with stout hind legs and bristles on their backs. Their spiny legs make it difficult to detach them from a host.

While cats and dogs are the primary carriers of fleas in your house, you can become a secondary carrier as well, especially in the absence of your pets. Adult fleas may stay in their pupal stage until favorable conditions cause them to emerge, such as increased temperature and carbon dioxide presence. Vibrations that indicate a host is near also stimulate their awakening. Fleas in unoccupied homes become active as soon as humans or pets re-enter.

 

Symptoms and Treatment Fleas are a general nuisance to their host, mainly because their bite causes an itching sensation. As a result, the host often tries to get rid of the pest by scratching or, in the case of lower animals, biting or pecking the general are of the parasite. Some people suffer allergic reactions to a flea bite, specifically the flea’s saliva, causing rashes. Only the female fleas bite. The bite generally results on an itchy, slightly raised swollen spot with a single puncture point in the center. They often appear in clusters of two bites, and they can remain itchy and inflamed for weeks. Other side-effects of the bites include hair loss due to frequent scratching and, in extreme cases, can cause anemia. If you find yourself suffering from flea bites, here are some tips you can take:

1. Clean the area. Use cold water and an antiseptic soap or lotion. Hot or warm water is generally discouraged as they may exacerbate the itching sensation. You may also use a cold patch on the flea bite in order to find relief from the itching. Use a washcloth to scrub the area, as this may remove other fleas in the area where you are bitten. Rub firmly but gently.
2. Don’t scratch the affected area. Scratching may lead to the breaking of the skin, bleeding and even infections.
3. Apply topical solutions to relieve itching. Anti-itch creams are available on the market and they can help you in relieving the itching and inflammation. Choose one that has antihistamines or hydrocortisones. Contrary to what most people say, calamine lotion is largely ineffective in treating itchiness.
4. Take oral antihistamines for severe allergic reactions. If topical applications and lotions do not offer relief from itching, then take oral antihistamines such as Dimetapp or Chlortrimeton. Before doing so, consult your doctor first. You may have other conditions that will worsen if you take oral antihistamines.

The results of applying these treatments will usually become apparent after a few days of having started them. It the itching and inflammation do not disappear after a week or so, then it is recommended that you see a doctor already. You might be suffering from another more serious condition. Check the flea bites to see if they worsen and if they appear to be more swollen. It's still best to avoid getting bitten by fleas altogether. Make sure your pets are regularly cleaned. Use anti-flea shampoos and treatments. Also, hire the services of a flea exterminator. That way, you’ll be sure that your house is flea-free and safe.