I had terrible ant problems in the yard when I lived in Santa Cruz, CA. I tried a mixture of brown sugar, molassas and active yeast that I got out of an article on natural pest control. Well-blended, they will take the mixture back to the nest and eat the yeast. It grows in their bodies and kills them. If you don't blend it well, they will just carry off the sugars and leave the yeast.
- Rae