Diatomaceous earth. Check on Amazon. I use Fossil Power. I used this in a window sill and no living ants left after a few minutes. I put some on the opening of the anthills and I'm not sure about the outcome, but I don't see any ants living or dead. I also sprinkled some in my yorkie's fur-she has a very oily coat and can be itchy, it worked immediately. She has never had fleas, but I'm thinking about using it this year instead of Frontline for the safety factor. Let me know how it goes |