I have Red Fire Ants on my little piece of the world.
When I mow I leave my mower set at it highest and leave the clippings on the ground to decompose and feed my lawn. The ants are very busy gathering the lawn clippings that have turned brown and building mounds for their nest.
Many of these mounds are quite large. One has been up to three feet in diameter and probably at least a foot high. This is a hugh colony of ants. It is out at the corner of my property where I barely notice it except when I hit it with my mower.
This picture of an ant colony is at the edge of a perennial bed outside of my front door. The picture was taken in the early morning hours while the ants were all still in the colony. This is a perfect time to take care of this colony.
A big pot of boiling water poured on this mound at this time would do a great deal in destroying this nest. Start around the edges and work your way in to the center very quickly. Be sure and wear protective clothing to avoid getting any splash of hot water or angry fire ants on your skin.
Natural enemies of fire ants have been tested for mass release for control of the ants in large areas, and progress is being made. Biological control agents include Beauvaria basisanna, a natural fungus disease that attacks them, and beneficial nematodes which can be found here => Beneficial Bugs Garden Pack. The beneficial bugs found in this pack are as follows: