How tf to get rid of horse flies? After the big deluge and now the heat, I see mobs of horse flies in my yard and some of them have found their way inside the house. I spray RAID and bleach everywhere or use the vacuum to suck them in, but more keep coming. How to permanently eradicate these pests? I dont even have any food lying around, I dont get why they are coming. I'm about to spray chemicals into my pond outside (it has no fish in it) to eradicate any insects that might use it for breeding or whatever.