There are over 2500 different species of mosquitoes throughout the world and most do not stray more than a mile away from their breeding site. Female mosquitoes need water to lay their eggs. They can produce 100-300 eggs at a time, forming groups that float upon the water's surface like rafts. Areas nearby creeks, lakes, and other slow moving or standing water are, therefore, the most heavily inhabited and should be avoided if one wants to avoid the dreaded mosquito bite.