Fire ants are one of the worst insect pests. If their mounds are disturbed, they become aggressive and will inflict painful stings.
A person can be in contact with a fire ant nest and not be aware of it until they have ants all over them. Some people are allergic to the sting, and the ants also interfere with agricultural operations, threaten livestock, and build unsightly mounds. On top of all that, they sometimes invade electrical boxes and destroy the wiring, as well as forage for food inside homes and other structures.
Fire ants are native to South America and were accidentally imported into this country back in the 1930s. The favorable weather of the Southeast, and the lack natural predators, allowed them to successfully spread and become established.
Unfortunately, fire ants cannot be eradicated over large areas and there is no silver bullet to control them. The main objective of any treatment methods is to kill the queen, because she is the only ant capable of reproducing, and there are several control options that have satisfactory results.
Pouring boiling water on top of the mounds is effective and usually kills most of the ants, although sometime the mounds will have to be re-treated. There are methods of chemical control for fire ants, such as an insecticide, which is applied directly to the individual mounds.
Individual mounds can be treated with an insecticidal drench, consisting of the chemical and diluted water, or with baits. The drenches act as a contact insecticide, and are effective if the solution drenches deeply into the mound. The ants will die within 24 hours. Ant baits are used to treat individual mounds, as well. The baits are insecticides mixed with ant attractants. Worker ants carry the baits into the mound, and feed it to the queen. The baits work well, but can take time - often one to two weeks to kill off the mound.
Another solution are broadcast treatments, which distribute an insecticidal bait over an area with multiple fire ant colonies. In areas with high mound densities, broadcast applications treat the area rather quickly. Broadcast treatments act as a preventative measure, and sometimes individual mounds will have to be treated with baits or insecticidal drenches.
It's best to stop fire ant invasions indoors before they happen. The prevention method is to remove open food sources, and seal up any cracks on the sides of a structure.
Keep in mind, when using pesticides, follow the label directions and take the necessary precautions to prevent the chemicals from doing any harm. Even though they are a menace, fire ant infestations can be reduced with proper control techniques.
Timothy Daly is an agricultural and natural resource agent with the Gwinnett County Extension Service. He can be reached at 678-377-4010 or firstname.lastname@example.org.