My fiance is from from Southern Texas as his parents always say 'the only way to keep fire ants out of your yard (and house by proxy) was to pour a 3 inch slab of concrete over your entire property...and your neighbors as well'.
His cousins' kid was almost killed at the play ground after falling into the sand box and disturbing a nest. The both ended up in the hospital for a few days.
I don't know that it would work - but I've used large saucers of soapy water to keep the black kitchen ants out of my enclosures. I used the plastic 10" drip pans for potted plants and set one under each leg of the table. Keeping the water soapy breaks the surface tension so the ants can't 'walk' on it. You just have to make sure the dishes don't dry out. It certainly won't stop them from coming into your home, but it may keep them away from your animals until you can find a way to stop them