Dawn dish detergent! I had ants that were marching in a special place on the foundation of the house. I sprayed multiple times and they kept on marching. Out of frustration I took the Dawn bottle out and squirted it in the trail and it seems to have worked! Also put it across the floor at the overhead door to the garage and they have moved out of there, too. The little white "huts" by Raid seem to have some deterrent, too, but the Dawn is apparently keeping them outside.