Red ants are also known as fire ants, because of both their color and the pain they inflict upon their enemies. Red ants can destroy a garden, using it for a food source until it is depleted. Because of colony sizes, distances between mounds to food sources and their ability to move quickly, red ants are often hard to control. There are various chemical and natural methods to eliminate colonies, although all of them can take several days to be effective.
Red ants are an invasive species. Colonies can reach 200,000 or more; the queen lays an average of 800 eggs per day according to Texas A&M University. Food for red ants includes oil-containing seeds, seed pods and other insects. Red ant colonies are dangerous because when one is attacked, thousands of soldiers emerge in defense. Fire ants sting with a venom similar to bees, have pincers to bite and can cause potentially life-threatening allergic symptoms for some people and pets.
While red ants live off seeds found in gardens, they do not always live in the garden or nearby. Mounds can be up to 18 inches tall and be located up to 75 feet away. Colonies are often in dense cover such as weeds or surrounding high grass. A common sign that an ant colony is nearby is the existence of an aphid colony in the garden. Ants feed off of the secretions of aphids; an ant colony will help build and protect an aphid colony within the same garden where ants gather seeds.
There are various chemical solutions to an ant infestation. Poisons containing spinosad and methoprene can be applied to the lawn and garden safely. These poisons create a contagious virus, which is spread through the colony as the ants return, according to the extension service at Mississippi State University. Liquid drenches with safe ingredients can be applied directly to a mound. Spinosad, permethrin and carbaryl are accepted poisons; acephate is not recommended because it can be absorbed by crop roots.
Natural solutions also work to eliminate red ant colonies. Removing the aphid colony eliminates a large food supply. Spraying aphids with a hot soapy mixture will kill adult aphids; introducing aphid predators such as ladybugs or lacewings also eliminates the colony. Boiling water poured directly onto and into the mound will drive off or kill the ant colony. Boric acid is effective but should be avoided if there are children or pets in the household.
Because ants are attracted to garbage, high grass and weeds, the best prevention is to contain the environment. Maintaining the garden, removing decaying or rotting plants and fruit, mowing the lawn and monitoring the garden are the best methods. Planting specific strong smelling plants will deter ants; mints, garlic and pennyroyal are examples. Spray the garden with lemon juice or hot pepper sprays because they contain acid.