Is this cluster fly
I live in Calgary, Alberta, Canada. Every year from Sept. to April, almost every day our acreage house has flies coming out in our office room. I am not sure they are cluster flies or not. All flies have yellowish color body and behave like cluster fly. I have exausted my efforts to find any possible cracks inside the house. They still come out. No sure what else I can do?
Outside United States
Cluster flies, like other flies, are a nuisance in the home. They may found an entry, or actually have hatched inside walls, etc. You can try the suggestions in this bulletin: http://healthycanadians.gc.ca/environment-environnement/pesticides/cluster-pollenies-eng.php
If you are still plagued by flies, I'd suggest you call a professional exterminator. But I do home this information is helpful