Ants in an organic garden aren't a problem, but inside the home is a different story. Here's what Organic Gardening magazine suggests:
1. Make a solution of 1 percent boric acid (available at any drugstore) and 20 percent sugar by thoroughly dissolving 1 teaspoon of boric acid and 6 tablespoons of sugar in 2 cups of water. Soak cotton balls in this bait solution. (Boric acid is a low-toxicity mineral, but do keep it away from children and pets because it can cause skin, mouth, stomach, and eye irritation.)
2. Make bait dispensers out of old plastic containers with lids. Punch holes in them so the ants can get inside, then put the soaked cotton balls into the containers and cover with the lid.
3. Place the bait containers wherever you see ant trails, inside or outside the house.
4. Clean the containers and use fresh bait solution at least once a week. Be patient! The key is to get worker ants to continually carry low doses of boric acid back to feed the ants in their nest.