Mar 27, 2015 - 07:22 AM
Flies just rest at night. They don't have a nest, a colony or anything. They just find a place to land and rest. This could be anywhere.
You might consider trying the Flies Be Gone Fly Bag. It does a great job of trapping flies by the thousands. Another great approach is to periodically spray the entire yard with Bifen IT. Spraying will kill flies on contact and help to repel others. It has to be done on a regular basis for best control.
Indoors, CB 80 is the best product to use. It's like a can of hairspray. Just point it at the flies and give them quick fog. They die in seconds. Works great around TV's, windows, etc. You can even fog an entire room in just seconds and kill the flies. That's what I use at my house.
Alpine Pressurized Fly Bait is also a very good product. Just point it and spray it on areas where flies land. They eat it and die. It can be used indoors and outdoors.
Hope this helps.