Cluster Fly

Typically found outdoors in fields and gardens during warm months; they enter houses and buildings to hibernate in wall voids or attics during winter.

Larvae are parasitic on earthworms; adults feed on plant nectar, fruit juices, and other organic liquids.

They are known for 'clustering' in large numbers in attics or window frames as cold weather approaches. They have a sluggish, clumsy flight and often drop to the floor when disturbed.

They do not bite humans or carry diseases associated with filth like house flies, making them primarily a nuisance. In the ecosystem, they help regulate earthworm populations.