I seem to have a colony of rover ants living somewhere in my hall bathroom. Behind the wall, or somewhere. I'm not sure. I recently had an exterminator come out and now I have no more ant problems anywere in or around the house. But, my hall bathroom on the far east side of the house has rover ants. I find them in the tub, in the sink, on the walls, on the floor, on the ceiling. A few here and there. I know they're in my bathroom for water, but I can't tell where they're coming from. Is there any way to find out what their point of orgin is? What crack in/under which wall they're coming through?