They may have won the battle but they will not win the war.
I do not know how they are doing it but the flies have not been defeated. I first thought I had them with the duct tape on the windows. But then, to my horror, I opened our back door and found them lining the door frame. I threw up in my mouth. That very night I had Jeremy double line the door with weather stripping to keep them out and I thought I had them for sure. But then today the temperatures were up in the 60s again and they returned.
I think the windows are installed improperly and they are somehow able to come and go as they please. OR they live in the walls and are just simply taunting me. I hate them.