In Spring and fall you may notice large, sluggish flies in your home; these are cluster flies. They are dark grey with black or silver, non metallic, checkered abdomens, and golden hairs on their thorax.  Their wings overlap when at rest, unlike house flies, and they are darker and slower.  They enter houses in the fall and hibernate in the walls, attics, closets or empty rooms.  They leave stains on walls & curtains; and emit a sickly sweet smell.  In the spring; they will migrate from their hiding places to  windows as they are attracted to light.  They do not breed, eed, or lay eggs inside the house.


Cluster flies are not a health risk the way blow flies and house flies are, due to their feeding habits.  In late summer and early fall, they will start looking for hibernation spots in crevices of south facing walls.  They will crawl into any small opening they can find in  house siding or under eaves.  You may not notice them until temperatures rise in the spring they become more active.


To prevent cluster flies entering the home; ensure all screens fit properly, and cracks or holes are sealed.  Weatherstrip all doors and windows, and caulk around frames and doorjams.  Install screening over any open air vents.  You can kill them with a fly swatter, but they emit a sickly sweet odour, and may stain surfaces.

If you have a problem with cluster flies; give Action Pest Control a call @ 905-318-1242, and we will look after you, we guarantee it!