I've had a lot of problems with ants in my potting soil for my veggies ie: tomatoes. One thing I've found that keeps them at bay is a sprinkling of cinnamon powder. I've also heared that coffee grounds will do same as will dilluted insecticidal soap.
I have never tried the coffee grounds, little success with the soap and moderate success with the powdered cinnamon.
I've also read that cotton ball with cinnamon, clove or peppermint oil will deter them.
Good Luck Bro!