I haven't tried to entirely eliminate ants, but discouraging them enough seems to keep them out of sight: when I find an ant trail on a counter, I clean that area thoroughly, remove the food that appears to be their goal, and maybe (depending on my mood) spray the nearer corners with generic crawling-bug spray ... but the only time I've seen a major occupying force has been when they've gone after Perrine's food, or (when anniemal visits) the food set out for Jamie (her poodle). I tried putting the cat dish inside a larger dish filled with water to make an ant-proof moat, but just putting a ring of ground black pepper on the floor surrounding her dish turned out to be just as effective and less hassle (despite looking much more slovenly). When they don't have access to what they want, I don't see them at all.