Grits will not work. It's just more food for the colony. I really think that a directed pesticide is the way to go. Like another poster said, a liquid poured into the mound is one way to do this. Another way to prevent the migration is to spray some vinegar. Ants lay a scent trail when they migrate and the vinegar interferes with their ability to detect the scent trail...they just can't "see" the road to take. Kind of like what would happen if you were to be blindfolded then asked to walk to a destination a mile away. Also, no, your chickens won't be harmed.
Since I moved North, I haven't had to deal with fire ants. They are pretty amazing, though in a somwhat dangerous way. Did you know that when they swarm they won't bite until the first ant makes the decision? Then, a chemical signal is produced and detected, leading ALL of the others to bite simultaneously. Amazing, but dangerous. It's easy to say things like that when the nearest fire ant is hundreds of miles away. Best of luyck to you, and keep us posted!
Since I moved North, I haven't had to deal with fire ants. They are pretty amazing, though in a somwhat dangerous way. Did you know that when they swarm they won't bite until the first ant makes the decision? Then, a chemical signal is produced and detected, leading ALL of the others to bite simultaneously. Amazing, but dangerous. It's easy to say things like that when the nearest fire ant is hundreds of miles away. Best of luyck to you, and keep us posted!