My yard has been over-run with ants all of a sudden.

I have to get rid of them but I hate using pesticides in the parts of the yard my pups go in.
I thought I read somewhere that cornmeal would kill ants? Is that true? Does it really work?
How do you apply it? How much should I use?
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He is your friend, your partner, your defender, your dog. You are his life, his love, his leader. He will be yours, faithful and true, to the last beat of his heart. You owe it to him to be worthy of such devotion. -- Author Unknown