Mixing fire ants from two or more mounds is another form of bio-control that will often work. When I notice a few mounds in the yard, I'll use a shovel to transport portions of each mound to other mounds. Sometimes, mixing 3 or more mounds together. Within 2 or 3 days, the ants are all dead. Occasionally, a colony might have enough survivors to begin rebuilding the mound, and I'll have to seek out more enemy troops from another mound outside of the yard's perimeter. In these cases, I have to run with the shovel full of ants, in order to reach the target area before the ants can crawl up the shovel's handle.
I learned of this method from an old farmer, who would drag his fields in order to mix-up fire ant mounds. His drag consisted of chain link fencing material, weighted with old automobile tires.
