That's terrible. You can kill the nests with homemade boric acid bait. You need borax (laundry detergent aisle), sugar, water, and something to put the bait in (bottle lid, cotton ball) and somewhere that little kids or animals won't get into, but close to where the ants are. The ants take the food back to the nest and they all die. Works like a charm. Best to put the bait near a line of ants, and just wait it out. Let them organize lines, and it's more efficient. I even used lines of DE to herd the ants where I wanted them. Ant invasion in my house was gone in 24 hrs.
½ cup of sugar dissolved in 2 cups of water, add 1½ tsp of borax. Soak cotton balls and set out in a lid or piece of foil and leave it. Or pour a bit in a small cap or lid (works great here where ants are always looking for water in summer). Lots of different recipes, but you need a balance between not so strong you kill the workers before they get it back to the nest, and strong enough to do in all the rest. If it doesn't work right away, play with the proportions a little.
That will work for sugar ants, but maybe yours want meat! If they want protein, you use peanut butter and boric acid. I forget the proportions, but I had ants take both baits and they just disappeared.
Here's a good link.
http://insects.about.com/od/HouseholdPests/a/How-To-Make-And-Use-Homemade-Ant-Baits.htm
