Cluster flies are grass flies or attic flies known for entering homes when outdoor temperatures begin to drop. They commonly go to the highest parts of your house, such as the attic, and come out of hiding when the sun shines and the outdoor temperature warms up. You may find them clustered around windows to try to get out.
Cluster flies are often mistaken for house flies, except they move very slowly and are somewhat lazy.
Cluster Flies Habitat
Cluster flies commonly hide in the cracks, crevices, and voids of your home once the outdoor temperatures begin to cool off. You can find them hiding behind curtains, picture frames, furniture, and underneath clothes inside closets.
They also like staying high up in the house and tend to exist in proximity to humans. They live in North America, Europe, Australia, and New Zealand.
Cluster Flies Habits
Once they turn into adults, cluster flies generally live near ground level, feed on flower nectar, plant sap, fruits, and other organic materials. Adult females lay their eggs near earthworm burrows so that their larvae can go deep into the ground and feed on the worms. Naturally, they are earthworms’ parasites.
Cluster Flies in the Heat
During summertime, the cluster flies like being outside because of the heat. They spend both summer and spring breeding, laying their eggs soon into larvae and feeding on earthworms. If cluster flies spent the winter in your home, you’d likely see them emerge from cracks and crevices as they find their way out.
Cluster Flies Inside Homes
These flies are generally attracted to light, which is why they like staying near windows during sunny days, but they’re also attracted to artificial lights at night. Unlike house flies, they are not attracted to garbage.
Cluster Flies Life Cycle
Each season brings about three to four generations of cluster flies. They begin as eggs, then larva, then pupa, they emerge as adult cluster flies in the spring. They commonly lay eggs between cracks in the soil, hatching in three or four days, then feeding on earthworms for two to three weeks.
The larva pupates in the soil for about two weeks, after which a new generation of cluster flies emerge. Their whole life cycle, from egg to death, lasts about one to three months.
Cluster Flies: Threat or Not
While they are generally considered overwintering pests and nuisance, they don’t bite humans or animals, except for earthworms. They also do not spread bacteria or lay eggs on food, so they don’t threaten human health.
Cluster Flies: House Pests or Not
If cluster flies entered your home to spend the fall and winter, they would generally stay out of your way. They’re spending the season to stay away from the cold temperatures outside but will then emerge in the spring or summer. Occasionally, they may also arise during sunny winter days to try to get out through your windows.
They are often lethargically floating around as if they’re in a zombie-like state. They may fall to the ground like they’re dead, but despite looking half-dead or dead, cluster flies won’t go away on their own.
Cluster flies may seem like a nuisance in the fall and winter, but they pose no health threat to you and your family. They can get pesky when they cluster by your windows, but they will generally stay out of your way.
Still, if you want to get rid of cluster flies in your home, you can contact ICE Pest Control. We are a residential and commercial pest control service in Toronto, Orangeville, Brampton, and nearby cities. We’ll take care of your pest problem instantly! Call us at 416-246-2256 and let us know how we can help!