if you don't want to kill them - get some black mint (it's called black peppermint sometimes) it has dark purplish stems and a strong smell - put several handfulls in a bucket, cover and leave for 4-5 days. Water the pungent mixture wherever there are ants and they will pack up and move elsewhere! I used this in my nursery when ants set up home in my tunnels - it doesn't hurt them or the surrounding plants, but they always moved.