We've had ant issues for a long time and we leave no food around. They've taken up residence where ever the can but mostly inside of the siding around the back of the house. I used terro for a few years and while it does attract a ton of them it didn't seem to affect the colony. I've used all kinds of bait and killers and so far nothing has been very effective. The gel bait made by RAID (i think) did really well one year.