Grits for Fire Ant Control
Abamectin is the natural product of a fungus, Streptomyces avermitilis, and is commercially available for killing mites and other insects including but not limited to ants and roaches. See Fire ants or the specific ants you have.
We have found that corn grits work better than orange oil. Use the regular or quick grits, not the instant grits.
The latter have already been expanded. If in doubt, check the weight on the box and the quick grits will be at least twice as heavy for the same volume as the instant grits.
We find that the quick grits work much better than the orange oil which has the tendency to kill grass. The grits kill all of the ants within 1 to 2 days while the orange oil may not. For that matter, grits works just as fast as most pesticides. But, the ants may come back as they will continue to hatch. In that situation, just apply more grits.
As far as the dried molasses and beneficial nematodes, ours were doing fine until late August. Before then if a mound started, the ants would die out within 3 or 4 days. But, with the hot, dry weather I believe the we have lost some of our nematodes near the surface. Some mounds do die, but some get large and have required the grits.
My wife claims she like to listen to the ants going pop.
David Griffith, Plano
Here is my take on why grits or cornmeal can inhibit Fire Ants.