Most mosquitoes have a lifespan of only around 2 to 3 weeks and during that time the mosquito may fly around 40 miles but usually the mosquitoes will stay near where they were born or where they have baby mosquitoes at.
Most of the mosquitoes never leave the town or location they are in until they die of natural causes or get squashed or sprayed by mosquito spray.
Some mosquitoes never fly no more than about 3 miles during their lifetime but some other species of mosquitoes will fly up to 40 miles.
The female mosquito is the one that bites humans and during the 3 weeks of life of the mosquito it can lay up to five clutches of more than 100 eggs each.
So the mosquito will reproduce even more mosquitoes as it lives even though it lives for only around 2 to 3 weeks.