We must have super ants down here. They walk through baking soda, borax, boric acid, vinegar (I've used up to a 30% solution, very stinky)... Cornmeal might work if they actually eat the stuff but not all ants do. Some actually eat molds that live in soil and wood, leaves, ... And sugar ants really don't seem to be after our sugar at all. Go figure. I really hate when the fire ants get into the electrical wiring, chew the insulation and cause a short. Finding their new mischief is always fun. It never fails to be behind the hardest to remove electrical conduit in the house. Last time it was the central A/C compressor wiring. Fortunately, a neighbor works on them and bailed me out.