Rob, I'd go on the fire ant website and download their information on treating them.
http://www.littlefireants.com/02%20LFA%2...202014.pdf
After reading the threads on here and hearing other people talk about how hard it is to get rid of them, I was prepared to pay someone to do it. But I thought, "What the heck" and tried using Amdro as directed and they disappeared almost immediately! I had them in the house but treated the outside perimeter as directed.
The one thing they stress is that there is two kinds of poison. You should bait first using hydramethylnon, so that the ants take it back to the nest, then apply a barrier of bifenthrin.
The barrier bifenthrin kills on contact so you don't want to use that until AFTER you've used the bait.
I'd give it a try before you pay someone. I've only used the hydramethylnon and it has worked really well. I had ants in June, they came back last week and I treated again. I probably should use the bifenthrin as a barrier but haven't as of yet.
You can get the Amdro ant block at Ace. Be sure to read the label to make sure it's hydramethylnon, they make several similar sounding products. Also, once you break the seal, it's only good for a couple of months.