I'm fairly sure that my house is being supported by nothing but ant hills. I've actually seen two of them near my front steps *shudder* This is concerning in and of itself, but it's also a pain because the little buggers get inside the house no matter what I do or how clean the house is (and ha! Let's face it, a house with kids is rarely sparkling clean).
But with the kiddos and pets running around, I really don't like spraying poison. So I googled around and found a few natural solutions.
Ants supposedly don't like citrus, lemon in particular. So, if you mix one cup of lemon juice with four cups of warm water and then wipe the mixture on counters, cupboards or wherever they are a problem. This is supposed to keep them away as they don't like the lemon scent
Again, ants supposedly don't like the scent so if you dust cinnamon along problem areas it should get rid of them. This one I have tried (in very small areas). I do think it helps and it does smell much nicer than poison, however I don't like having trails of brown dust all over the place. I've also mixed it with water to make a paste and shoved it in cracks where I've noticed ants coming out and that wasn't quite as bad.
3. Baby powder
Supposed to work like the cinnamon. Just sprinkle it around problem areas.
Ah, another use for the magic that is vinegar. Mix this stuff 1:1 with water and spray on ant trails. I've also seen some people suggest adding a tablespoon of peppermint oil to the mixture.
There is a slightly more elaborate solution that apparently works really well. I found it at The Happy Housewife. You'll need 1/2 cup sugar, 1 1/2 cups Borax, 1 1/2 cups warm water, and some cotton balls or cloth. Head to her blog for full instructions but she had a lot of success with this method so it's worth checking out.