Terro works, but you have to give it time. We have big black ants in the kitchen and little black ones in of all places, the bathroom sink. I havekept Terro on the sink for about two weeks,and they were coming in droves and I couldn't keep it on the little cardboard pieces as they ate it so quickly. Today, I noticed there aren'tany there. I hope they have taken it back and killed the colony. If I see the big black ones in the kitchen, I just put some on the cardboard at night and the next morning they are nowhere to be seen. This keeps them away for a week or two and then some more venture out. I have about eliminated them inthe kitchen. I know Terro works, you just have to give it time.