Sweet Peas and Pumpkins: Homemade Earth-Friendly Weed Preventer --- gal vinegar, lemon juice, 1 tbsp dish soap. Safe enough for the kids to use! Also, good ideas on getting rid of ants in the comments.
Simply pour 2 cups of CLUB SODA directly in the center of a fire ant mound. The carbon dioxide in the water is heavier than air and displaces oxygen which suffocates the queen and the other ants. Each mound must be treated individually.