You may have seen Cluster Flies migrating in groups around your windows. They are smaller than regular house flies and generally slower moving. During mid to late August, Cluster Flies begin to migrate indoors, through window cracks and door frames, looking for a warm place to overwinter. These pests don't pose a risk to homeowners, but become a nuisance when their numbers increase and they find their way inside. But, where do Cluster Flies come from?
Cluster Fly larvae develop inside earthworms living in the ground outside of homes. The larvae develop into cocoons before hatching into adult flies. The adult flies are attracted to the sunny side of homes in the fall, looking for ways to get inside before winter. Don't worry, Cluster Flies do not breed indoors. They are only looking for a warm place to overwinter, before emerging during the warm spring months.
If you've seen Cluster Flies around your home contact a licensed pest control technician. Pest proofing your home (sealing cracks and crevices along windows and doors) and treating the structure annually is the only way to get rid of these flying pests.
Was this information helpful to you?