Wondering if anyone can say what the heck is up with a large swarm of flies I seem to have in my garage... They seem to be located around some insulation on an interior wall between the car space and the workshop, it's a detatched garage. No roof leaks, but the concrete floor does tend to sweat. I don't think there's any dead animals, but I wouldn't be surprised. There isn't any noticeable dead animal odor. A few months back I had a dead squirrel under some lumber on the floor, but I peaked into the rafters and didn't see anything obvious.