The problem is defining what is meant by the term "organic." Fire ant control methods considered to be organic usually include cultural, physical, mechanical and biological control techniques. Also some chemical treatments are considered to be "of natural origin," such as plant derived (botanical) insecticides. The fire ant bait containing spinosad has been certified as organic because it is derived from a soil microorganism. It is sold under various trade names, including Ortho Fire Ant Bait and Fertilome Come and Get It. Certain formulations of spinosad or citrus oil and other plant-derived compounds can be mixed with water and applied as a mound drench. For more information, see the Texas Cooperative Extension System publication, Organic and Other Methods of Fire Ant Control. (PDF)

Additionally, hot water can be poured on the mounds but it only kills ants soaked with very hot water. Pouring approximately 3 gallons of very hot water onto a mound will eliminate the colony about 60% of the time. Drench mounds when the ants are close to the surface, such as a cool, sunny morning in the summertime. Use caution, as you risk damaging plants or grass, and even burning yourself.