I have three daughters and two sons so I'm already prepared to be "wrong" a lot.

Kill them all. They really have no natural enemies in Texas that I am aware of. Diesel injected down into their mound works well. Boiling water is a great quick fix.

Check this out. Someone is bringing in the fire ant's natural enemy from South America. They only target fire ant's, no others. How do we get some of these in Texas?
https://m.youtube.com/watch?v=UiJgsPUYahs

Gas is more fun.

I will give you 2 reasons t o at least kill the ones close to the house.

#1 - they will fry the contacts on you AC unit and get in to septic air pump if you have one

#2 - they love cotton as in cotton underwear. I was in a hurry one morning and picked up a pair of underwear off the floor that was lying next to an exterior wall. By the time I got from the north side of Roanoke to Southlake I was pulling off the road and stripping down on the shoulder. A couple hundred fire ants on the junk is not fun. Glad it was still dark outside.

I thought about trying this method.

I've heard drilling mud can really wipe out a colony

I would try the casting if I didn't have bedrock within 12 inches. It sucks digging around here.

Not actually, the horny toads didn't get eaten by the fire ants. the main food source to the horny toad was the carpenter ant. the fire ants being as invasive and territorial as they are, wiped out a lot of the carpenter ant population so the main food source of the horny toad disappeared, thus the disappearance of the horny toad. Used to be carpenter ant beds everywhere but not now.

I keep a container of orthene always on hand. kick the top of the mount off so they go crazy and sprinkle that orthene on the mound and watch them die in agony!!!! It makes me smile.....and they are non-existent the next day. Sometimes they move but then i get them the next weekend. Spot treating the mounds like this really is effective if you do i during the spring. then you have the summer with no fire ants.

Phorid flies work well at controlling fire ants but the problem is with the in-ability of the Phorid fly to survive the winter. The phorid fly comes from the same area climate the fire ants came from but the fire ants can go deep underground to survive the winter where the flies all die out and reproduction for the next year never happens. I think they have had some success with them in places like south Florida where winter is basically non-existent.

It might work in south texas below the frost line.

Awesome! Learn something new every day!

i had a waterbed on the 2nd floor of my house...the heater quit so i drained the water to get to the heating element...yep...fire ants shut it down...and they are called FIRE ants because when you get bit and it festers and you squeeze it, it feels like FIRE...