Where do flies go in the winter? Do they die, fly to warmer climates, or hibernate?

When cold weather arrives, it may seem like flies simply disappear, but many are closer than you think. Common houseflies and cluster flies survive the winter by entering a state of insect hibernation known as diapause. To do this, they seek out sheltered, dry, and warm locations where they can remain dormant until spring. Your home's attic, sheds, barns, and even the voids inside your walls make for perfect overwintering spots. This is why on an unseasonably warm winter day, you might be surprised by a few sluggish flies suddenly appearing near a sunny window, having been temporarily woken by the heat.

This survival strategy applies mostly to adult flies, but the species has other ways to make it through the cold season. Many flies overwinter in their immature stages. Eggs, larvae (maggots), or pupae can lie dormant in protected places like soil, compost heaps, or other decaying organic matter. Once the ground thaws and temperatures consistently rise, they resume their development. This ensures that a brand new generation is ready to emerge as soon as conditions are favorable, continuing the life cycle for another year.