I have a sunroom on the back of my house that has gotten a fly infestation. It started in late October and has continued to the present. Everyday I have to go out to it and kill at least 5 flys. They congregate where ever the sun is shining obviously for the warmth. There is no garbage out there and no central air vents. This is a real nuisance since I can't really use the sunroom unless I clean it everyday. I originally had some plants out there but since have removed them. Any ideas would be helpfull.