Good morning, it was nice speaking with you today! I completed your quarterly service today. I inspected throughout the interior for the source of the flies, but was unable to find anything. It is likely a dead rodent in the walls that we are unable to reach. The flies will go away, given time. I checked the rat trap and exterior bait station and found no rodent activity at this time. I then treated the exterior perimeter, as well as around doors and windows, with a liquid residual for ants, general and seasonal pest activity. Please allow two to three weeks for full effect. If you have any questions or concerns, please give us a call. Thank you for choosing Green Pest Solutions!