Ants in plant roots

I would firstly take container plants out of the pots, if you can. Then take your root ball and soak it in water for two days and clean out your container. Re-pot with fresh potting soil. Then put ant baits into the soil around your plants. You can also stick ant baits in potted plants. The ants are supposed to take the poisonous material in the trap back to the colony and hopefully kill the queen.