Red ants are best killed with hot water and soap, according to Organic Gardening magazine. Additionally, many commercially made products are effective in killing red ants, however, most are harmful to the environment, animals and children, making it important to use them responsibly.
To use the hot water method, simply heat water to scalding and pour the water on a red ant nest to kill its inhabitants, according to Organic Gardening. The downside of this method is that hot water kills both grass and plants, as well as causes burns, when spilled, so use this method with caution. The bucket and drown method is one of the best ways to eradicate one or two problem mounds. Before using this method, wear long pants tucked into socks and sprinkle the nest with baby powder or corn starch to prevent the ants from coming out of the nest. Dig up the mound using a shovel and quickly put its contents into a bucket. Fill the bucket with soapy water to drown the ants.
Organic Gardening does not recommend using household cleaners and other products not developed to kill fire ants. Many of these products simply disturb the ants' nest, causing the colony to rebuild, typically just a few feet from the old colony.