I normally do not have ants except that they get in the cat's food and the dog food.
Doggies and cats do not like to compete with ants for their food.
I ordered a pack of diotomaceous earth and make a bait out of ant infested cat food and d.e. put a lose lid over it and let the ants have at it.
Possums raid my front porch at night for left over cat food. They eat the left over food, ants, d.e. and all. They really don't mind eating live ants either.
Ants are good to have around because they are scavengers--the cleaner uppers. In fact if you have them its probably a good sign that you need to upgrade your cleaning habits--or find better ways to store your pet food.
Ants help protect your house by eating termite eggs and larvae: http://drdons.net/do-ants-kill-termites
In fact I notice an add at the bottom of this page for controlling termites with ants.