Pour the mound drench formula into the center of the viable mounds and apply beneficial nematodes at label directions.
Here's the mound drench formula. Mix equal amounts of compost tea, molasses and orange oil.
Use 4-6 ounces of this concentrate per gallon of water and use as a drench to kill fire ants and other pests in the ground. Use a container that pours a solid stream of liquid. Pour into one spot in the center of the mound. This causes the mix to go quickly to the bottom of the mound where the queens will probably be kept. Then pour the remainder of the mix in a circular pattern covering the entire mound. You might want to save a little to splash those ants trying to run away or worse, up your legs.