Mosquitoes have been aound for about 200 million years. Their brains are about the size of a pinprick. A typical mosquito weighs about 2.5 milligrams, about 20,000 mosquitoes to a pound. Tropic regions have the most varieties of mosquito species, but the Arctic and Antarctic regions are home to larger populations. There are more than 3,000 species worldwide, but the United States has only about 170 species.
Some people are more attractive to mosquitoes because they smell better.
Mosquitoes live in a chemical world and carbon dioxide, lactic acid, natural skin oils and heat attract the pests. We are easy prey because we're big and smelly, and there are a lot of us to bite. Because of the diseases they spread, mosquitoes kill more humans than do any other animal. Malaria affects 300 million people per year and is transferred to humans soley by mosquitoes. Mosquito species found in Alaska are not known to cause disease.