By Gyman Okeson
Special to the Daily Herald

Anyone who actively gardens in Texas is familiar with fire ants. These pests not only cause unsightly mounds to grow up almost overnight in our flower beds and lawns, but the ants are known for their aggressive behavior and their potent sting that usually causes multiple small ulcerations and more than a little discomfort.

Their presence is particularly annoying when they nest in a compost pile. They usually make their presence known when you dig into the pile to retrieve some compost to use while transplanting a favorite plant, only realizing too late the pain of their sting as they swarm up your limbs. Fire ants will not go away by themselves. They continue to multiply and can cause real damage. If there is only one mound in evidence, be aware there are multiple ones unseen and most mounds have multiple queens.

Most of the usual commercial remedies are potentially toxic to humans. In addition, they require time and multiple steps before they reach the queen so that colony destruction can occur. Commercial contact poisons often result in the colony just moving to another location. The ants will usually not accept corn-meal baits that have been stored adjacent to petroleum or fertilizer products. One “non-toxic” method of killing a mound consists of pouring boiling water on it. The fact that the queen of a well-developed colony may live as deep as 30 feet below the ground and up to 20 to 50 feet from the visible mound explains the poor results gained from this method. Also handling boiling water is not very safe.

There are two other non-toxic, environmentally friendly methods that you may want to try to kill fire ant mounds. The first method, originally espoused on a Georgia gardener radio program, consists of pouring two cups of club soda (carbonated water) directly onto the center of the mound. The carbon dioxide in the club soda is heavier than air and displaces the oxygen in the passageways of the colony, suffocating the queen and other ants. The entire colony will become dormant in about two days. The soda leaves no poisonous residue, and is not harmful to pets or other animals. One liter of club soda will kill 2 or 3 mounds.

The second method, which works faster than the club soda method, consists of mixing a half-cup of dish soap (any kind will do) in a gallon of water and then pouring it directly onto the center of the mound. The soap dissolves the waxy outer coating of the ant’s exoskeleton causing it to overhydrate or dehydrate (depending on the circumstances), resulting in rapid death. I have seen a colony become completely inactive within 30 minutes using this method. Again, the method is non-toxic and environmentally friendly.

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