Mosquitoes are relatively fragile insects with an adult life span that lasts about 2 weeks on average, depending on species. The vast majority meets a violent end by serving as food for predators, or are killed by the effects of wind, rain or drought. The mosquito species that only have a single generation each year are longer lived and may persist in small numbers for as long as 2-3 months if environmental conditions are favorable. Mosquitoes that hibernate in the adult stage live for 6-8 months but spend most of that time in a state of torpor (hibernation). Some of the mosquito species found in arctic regions enter hibernation twice and take more than a year to complete their life cycle.