Unfortunately, many insects don't survive the freezing cold of winter. Others, however, have come up with clever schemes to hang on until spring. For example, cluster flies sometimes hide out in the nooks and crannies of a warm house or barn over the winter, venturing out to fly around only on milder winter afternoons. Mosquitoes, like bears, hibernate through the winter cold. Once they've had their blood meal, they're ready to lay eggs, and hatch a new crop to plague us during the summer.
Some mosquito species do things differently.
In summer they lay their eggs. The adults die off. But all through fall and winter the eggs lie still, actually freezing when the weather turns nasty. When the warm rains of spring finally come pelting down, the eggs thaw and hatch. Some water-dwelling insects burrow into lake and river bottoms for the winter, and some beetles hibernate in tree bark.