If you are noticing cluster flies in the home, especially around windows or in sunny rooms, they may have entered the house months earlier while searching for a warm place to spend the winter.
What Are Cluster Flies?
Cluster flies are larger and slower-moving than common houseflies. They often gather or “cluster” in large numbers on sunny exterior walls before entering through small cracks and openings around windows, doors, siding, soffits and rooflines.
Once inside, they typically remain hidden in attics, wall cavities and other protected areas. On warmer days, they may become active and appear around windows as they try to make their way back outside.
Why Do Cluster Flies Enter Homes?
Cluster flies enter buildings in late summer and early fall to find a protected place to overwinter. Even very small openings can provide access to the home.
Although cluster flies are a nuisance, they do not usually reproduce inside the house. The flies you see during the winter or early spring are generally the same flies that entered in the fall.
How Can Cluster Flies Be Prevented?
The best time to help prevent a cluster fly problem is before they enter your home. A preventative exterior treatment applied at the appropriate time of year can help reduce the number of flies that find their way indoors.
It can also help to seal cracks and gaps around:
- Windows and doors
- Siding and exterior trim
- Soffits and rooflines
- Vents and utility openings
- Other possible entry points
If flies are already appearing indoors, they can be removed with a vacuum. Avoid crushing them, as they may leave stains on walls, curtains and other surfaces.
Need Help With Cluster Flies?
Andy’s Pest Control provides safe and effective cluster fly prevention and control services throughout Peterborough, Northumberland, Kawartha Lakes and surrounding areas.
If cluster flies have been finding their way into your home, contact Andy’s Pest Control to discuss treatment options and learn how a seasonal preventative service may help.
