Cluster Flies in Ontario
Cluster fly identification, seasonal attic activity and exterior entry prevention in Eastern Ontario.
What cluster flies look like
Cluster flies are slightly larger and slower than typical house flies, with a dark body and fine golden hairs. They often appear sluggish near sunny windows.
Where activity develops
Adults enter structures in late summer and fall to overwinter in attics and wall voids, then emerge on warm winter or spring days.
Signs worth documenting.
Slow flies at upper-storey windows
Large seasonal groups in attics
Activity returning on sunny days
Make the property less favourable.
Prevention depends on correct identification and the conditions supporting activity. These steps are a practical starting point.
Identification before treatment
Similar-looking pests can require very different responses. Avoid applying a product until the pest, location and permitted label directions are clear.
Serving Eastern Ontario
Emerald Pest Control serves Belleville, Kingston, Trenton, Napanee, Brighton, Stirling, Picton, Quinte West and surrounding communities.
Not sure whether it is cluster flies?
Send a clear photo and tell us where it was found. We can help confirm the pest and discuss appropriate next steps.