Mosquitoes have two pairs of wings, but their second pair of wings are reduced to short, peg-like structures called halteres. Mosquitoes have thin, long bodies and three pairs of extremely long legs. They have scales along the veins of their wings and long beak-like, sharp sucking mouth parts called a proboscis. These two features distinguish mosquitoes from other flies. Mosquitoes also have feathery or hairy antennae.
Female mosquitos are ready to mate within a few hours after reaching their adult stage, and males are usually ready within 24 hours. Mating typically occurs while the mosquitoes are in flight, but sometimes it occurs on the ground. The tone of the female wing beat attracts males, and they grab the females with their hind legs. Mating among mosquitoes is related to their swarming habits, which in some species, but not all, is the preliminary behavior to mating. Swarming usually occurs around sunset and near fences or other objects and can last from 10-30 minutes.
Mosquitoes feed on sweet nectar, fruit, and other sugary substances. The females of some mosquito species also feed on blood, which they need in order for their ovaries to mature and for their eggs to develop. The female blood meal can take place before or after she has mated. Female mosquitoes detect their blood hosts partly through the sense of smell and partly by sight. The distance over which a mosquito can detect a blood host can range from 20-90 ft (6-27 m). Research indicates that mosquitoes are attracted to hosts already under attack by other mosquitoes. Some adult male humans are more desirable to them than women or children. Human beings are not the only blood hosts that mosquitoes attack. This "vampire" of the insect world is known to feed on mammals, birds, lizards, fish, bats, and even caterpillars for its blood meal.