Ant nests go through phases. Sometimes they are after sugar, other times they are after protein. I have sold an abundance of chemicals for 2 decades working in garden centers. I now primarily use Orthoboric acid. It is a white powder, very safe around pets and small children. I made the mistake of storing one bottle under the sink, and it caked up, but sprinkle or dust the trail and access places, and they stay clear. It is a little messy, but I only use chemical if I really need it. Ants clean themselves constantly, so one dusted ant bumps into all his friends and so on, and so on. It is about control, not eradication. Ants kill termites, (although carpenter ants are another issue), so killing all ants are not a good idea if you live in a wooden house. Keep outside in small #s. If all fails, unionize them like Ren said. That is brilliant integrated pest management.