Well, since you've been awesome at giving me advice on MD's...
I know you said no poison, however Borax works extremely well on most ants. It's natural but still you don't want to ingest it.
We had a substantial ant problem a couple of months back and I tried a couple of different mixtures of sugar, Borax and water. Basically, it needs to be a 2:1 ratio of sugar to Borax.
Mix the dry ingredients and then add just enough water to make it like a wet concrete. Even if all the sugar granules don't dissolve in the mix, they will in the heat.
Find the path that these ants are traveling and pour the mixture on and around the path. If you can find where they're living its also a good idea to place it there but they'll being it back to the nest.
Basically, they like nectar and this mixture is tasty for them. The Borax, however, creates gases in their gut and they can't rid themselves of it causing their insides to pretty much rupture. The key is to make the right mixture so they don't die before getting back to the nest.