Cluster Fly

Cluster flies resemble house flies, but have fine golden hairs on their thorax. These flies are parasites of earthworms, but happen to sneak indoors in late summer and early fall to find a sheltered overwintering spot. If in a warm enough spot, these flies can become active during the winter months and wander aimlessly around windows.

Extension Bulletin

Cluster Fly
Cluster Fly
Cluster Fly
Cluster Fly
Cluster Fly
Cluster Fly