I moved into the house in the middle of October so it wasn't really a problem. I noticed there were quite a few of the packages for the bug collecting traps in the garage though. It wasn't until the following summer that I noticed the problem. I suspect it was due to a drainage ditch in the county park my yard butted up against, but the number of rather large and biting horse flies made being outside intolerable. So I broke out one of these thick plastic baggies, put a little water in it according to the instructions, and hung it up.
I was totally unprepared for the level of carnage that followed.
After only a couple of days, I had collected thousands of dead or dying flies in the baggie. They were able to climb in to get at the attractant that smelled of decaying flesh and ultimately added their own. I was replacing full up baggies with new ones every other day for a few weeks, and I figured I'd killed every fly in a 5 mile radius. Thousands and thousands of dead bugs.
Unpleasant, but super effective.