I’m originally from Texas, too so I know the problems you’re having with those ants! The only thing I found that worked is a product I bought at Wal-Mart called Amdro. It’s amazing. It’s a granulated poison. You pour it on top of the ant bed. They are very attracted to it and take it down into their tunnels where they all eat it – including the queen (which is what you want to get rid of). In a matter of a couple hours, you’ll notice less of the ants. In a couple days, they’re gone.
You’ll have to treat each bed that you see even though they are most likely connected. The product is kind of expensive. I think I paid about $10 for a small canister of it. But, that’s much less than hiring an exterminator.