Some species, for example Aedes excrucians, are tolerant of a variety of situations, breeding across Canada from the treeline south, but most have their preferred habitat. A few may be found only in large permanent marshes. Temporary snowmelt pools support the greatest number of species, mostly species of Aedes, and perhaps also the greatest number of individuals. The drying up of these pools in summer is of no consequence once adults have emerged from them, because their eggs survive desiccation, sometimes for many years. Even specialized habitats, such as the water in tree holes or pitcher-plant leaves, contain species of mosquitoes found nowhere else.
Temporary pools form ideal breeding places for species that can develop fast.
Predators, which cannot develop appreciably more rapidly than the mosquitoes, face a glut of food for a few days which they cannot consume fast enough, followed by an abrupt disappearance of this food. Although many kinds of predators have evolved to exploit this abundant food source, few are effective enough at significantly reducing the numbers of larvae to be exploitable as biocontrol agents. Parasites and disease organisms also have their difficulties adapting to such a rapid change from feast to famine. Mosquito larvae, also called wrigglers, are surprisingly complex animals anatomically. They have no legs but can swim rapidly by lashing their body from side to side.