There are more than 2,700 species of mosquitoes in the world, and there are 13 mosquito genera (plural for "genus") that live in the United States.
The mosquitoes are insects which make up the family Culicidae. They have a pair of scaled wings, a pair of halteres, a slender body, and long legs.
The females of most mosquito species suck blood (hematophagy) from other animals, which has made them the most deadly disease vectors known to man, killing millions of people over thousands of years and continuing to kill millions per year by the spread of diseases.
Depending on the species mosquitos can grow to 4 to 6 mm long. Only the females bite and suck blood, which they need for reproduction. The males do not bite.
Usually the mosquito larvae grow in stagnant (dirty) and shallow water. Moisture and heat speed up the developing cycle of the larvae.
Mosquitos are mostly active in the time between dusk and dawn - on warm humid days in the afternoon as well. In the daytime they usually hide in moist shady places such as hedges and woodland, or in houses.
They are responsible for transmitting the commonest infectious diseases throughout the world.