Krissim,Have you tried to locate entry points? You may be able to seal those and keep the ants out permenently. Have you tried to locate and treat the ant colony directly? Depending on the ant species, you could wipe the colony out with a commercial ant bait. A bait called Amdro works well on a large number of species in the US. Sometimes you just need to grind it into smaller pieces. HAve you tried to spray just the exterior of the house? Treating the exterior may be enough and you don't need to hit the interior at all!