Flea

Flea is the common name for insects of the order Siphonaptera which are wingless insects with mouthparts adapted for piercing skin and sucking blood. Fleas are external parasites, living by hematophagy off the blood of mammals (including bats and humans) and birds.

Fleas are small (1/16 to 1/8-inch (1.5 to 3.3 mm) long), agile, usually dark colored (for example, the reddish-brown of the cat flea), wingless insects with tube-like mouth-parts adapted to feeding on the blood of their hosts. Their legs are long, the hind pair well adapted for jumping: a flea can jump vertically up to 7 inches(18 cm) and horizontally up to 13 inches (33 cm). This is around 200 times their own body length, making the flea one of the best jumpers of all known animals (relative to body size), second only to the froghopper.

Fleas are holometabolous insects, going through the four life cycle stages of egg, larva, pupa, and imago (adult). The flea life cycle begins when the female lays after feeding. Adult fleas must feed on blood before they can become capable of reproduction. Eggs are laid in batches of up to 20 or so, usually on the host itself, which means that the eggs can easily roll onto the ground. Because of this, areas where the host rests and sleeps become one of the primary habitats of eggs and developing fleas. The eggs take around two days to two weeks to hatch.

Fleas (Parasite) are not only a nuisance to humans and their pets, but can cause medical problems including flea allergy dermatitis (FAD), secondary skin irritations and, in extreme cases, anemia, tapeworms, stomach flu. Fleas can transmit murine typhus (endemic typhus) fever among animals and from animal to humans. Also, fleas can transmit bubonic plague and any other disease from human to rodent and from rodent to humans. Tapeworms can infest in humans in severe cases.

Although bites are rarely felt, it is the resulting irritation caused by the flea salivary secretions that varies among individuals. Some may witness a severe reaction (general rash or inflammation) resulting in secondary infections caused by scratching the irritated skin area. Others may show no reaction or irritation acquired after repeated bites over several weeks or months. Most bites usually found on the ankles and legs may cause irritation or pain lasting a few minutes, hours or days depending on one's sensitivity. The typical reaction to the bite is the formation of a small, hard, red, slightly raised (swollen) itching spot. There is a single puncture point in the center of each spot. (Ants and spiders leave two marks when they bite. Mosquitoes, bees, wasps and bedbugs cause a large swelling or welt.