When I lived on the farm, I noticed that the big red ant mounds had no fire ant mounds within hundreds of yards. The big reds are mostly docile. I would always feed them scraps that the dogs wouldn’t eat.
I have also witnessed armadillos dug into fire ant mounds munching on whatever the fire ants had stored inside the mound.
Diatomaceous earth and borax will kill fire ants. So will dry or liquid horticultural molasses.
One of the best ways to alleviate the stings is a dip in a chlorinated swimming pool or bathtub.
A small cup of bleach will kill the mound......................