What do cluster flies look like?
Cluster flies are a large species of fly; adult cluster flies can grow up to ½ of an inch long, which is slightly larger than the common house fly. These flies are often confused with house flies, but it is important to understand that they are two totally different species. The body of the cluster fly is long and narrow. These flies are dull gray in color; cluster flies also typically have dark black and golden-colored hairs on their thorax and legs. When at rest, the wings of these flies overlap at their tips, while the wings of the house flies do not.

Are cluster flies dangerous?
Unlike many other species of fly, cluster flies do not lay their eggs in the food that we eat, and are not known to transmit serious diseases to people.
These flies are considered nuisance pests, but pose no real threats to people or pets. Cluster flies are a danger to the earthworm, however; cluster flies lay their eggs near earthworm burrows so that when their larvae hatch, they can penetrate the bodies of earthworms and feed on them
Why are cluster flies on my property?
Cluster flies invade homes and other warm buildings in the late fall while seeking a place to overwinter. The attics, crawl spaces, and wall voids found inside these structures offer cluster flies refuge from the cold winter weather outside.
Cluster flies become a nuisance on warm, sunny days as they emerge from their hiding spots and “cluster” around windows, light switches, light fixtures, and doors.
How do you get rid of cluster flies?
Cluster flies can be difficult pests to eliminate because they tend to hide in the hard-to-reach areas of your home; therefore, getting rid of cluster flies f is a job that should be left to the pest control professionals.
When you contact Spencer Pest Services, we’ll dispatch a Service Professional to inspect and treat your property with effective pest control methods designed to eliminate and prevent pests.
For more details on how our team can resolve a cluster fly infestation in your home or business, please contact us.
Cluster fly prevention tips
To prevent cluster fly infestations, we recommend the following tips:
- Make sure that screens placed in your home’s windows and doors are completely intact.
- Seal cracks found in your home’s foundation.
- Replace any missing or broken roof shingles.
- Repair any holes found along your home’s roofline.
- Cover all vents around your home with tight-fitting covers made of mesh.
- Seal any spaces around the utilities that are entering your home.
Of course, we also suggest implementing a home pest control plan that protects your home and family from pests all year-long. To learn more about Spencer’s comprehensive and affordable pest control services, please visit our residential page.