Ants in Gr Biting Dog!?

My house has a severe ant problem (the former owners forewarned me). I can usually keep them at bay w/ vinegar, salt, etc. inside. And, I've used boiling water on the mounds outside, tho it is not great for the gr. My biggest concern is they bite my dog like crazy when she's out romping in the yard. She already has about a dozen bites on her legs & shoulders, and the ant season is just starting! I may try throwing instant grits or cornmeal all over the yard...any problem for the gr or birds? I know if you "season" your dog's food w/ garlic powder, it gets into the skin, and can repeal mosquitoes. Has anyone had any success w/ food supplements for this problem? Thanks!