This is one of those "boy, that sounds to good to be true" stories. This kind od sounds similar to feeding ants dry grits that will cause them to them swell up and explode, a nice story but something that does not happen.
What is the feeling about this from the people at your Texas A & M USDA Cooperative Extension Service office? These people have done considerable research in control of Fire Ants.

Here is a link that might be useful: Fire Ants

In no way am I saying this is true but............My uncle told me that if you have two seperate mounds of fire ants. You and another person, each of you with shovals, scoop out about halfway down through the nests and then swap them. Supposedly the ants from the opposing nests will kill each other. Sounds far fetched but I may try it one day when I'm bored.

clinda62, the sting of the fire ant is probably due to formic acid and the soda is carbonic acid. It is feasible that some biochemical reaction between the two acids in the bodies of the ants will result in death.
If one accepts the proposition that the survival unit is the HIVE and not the individual BEE and extend this to the fire ant mound, the second control method is also credible.
The "transplants" will be treated as invaders and battle it out. There is bound to be a lot of casualties from such a skirmish.
Aside: Long ago and far away, an old farmer warned me to 'watch for caterpillars whenever there is lightning and thunder with no rain'. Over the years I observed this to be the case on the few occasions when the conditions occured. Of course caterpillar outbreaks happened in other and different conditions but 'the observation often precedes the science'.

From his website Walter Reeves states he did not endorse this method, but was curious to see if it works.
Read link below.
Shot

Here is a link that might be useful: Walter Reeves Website

Hi,

I happen to know that they definitely do not like mint. In the past, I have actually taken a shovel to them, dug into them until I found the larvae and killed them. So far this year, I haven't had a problem with them in my yard, but if they do show up, I'm going to make a "mint tea" to treat any mounds.

Hope this helps,

Olyveoil...(O:
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