Physical and Mechanical Methods
Pouring very hot or boiling water on a mound is a fairly effective treatment, particularly when ants are close to the mound surface such as on a cool, sunny morning or after heavy rainfall. Approximately 3 gallons of very hot (almost boiling) water poured on each mound will eliminate about 60 percent of the mounds treated. Be careful handling large volumes of hot water to prevent serious burns, and keep hot water off of desired plants and grass. A number of hot water or steam injection devices have been produced for treating individual ant mounds.
Sometimes it may be sufficient to move colonies away from sensitive areas such as gardens. Disturbing or knocking down mounds frequently will cause colonies to move. Individual mounds can be carefully shoveled into a bucket dusted on the inside with baby (talcum) powder and the ants drowned with soapy water, but this rarely eliminates all ant colonies in the area. Some people believe shoveling one mound on top of another will force ants to kill each other, but this is not true.
Certain barriers can keep ants out of sensitive areas such as duck nesting boxes or greenhouse benches. Talcum powder and Teflon®-like tape or spray products can be used on vertical surfaces, but these treatments lose their effectiveness in humid or damp conditions. Tanglefoot®, a petroleum-based, sticky material available as a gel or aerosol, is effective temporarily until it becomes coated with dust and other debris. Plates or wires heated to about 140 degrees F form a hot barrier that ants will not cross. Some plastic repellent barrier products impregnated with permethrin are now available (AntGuard®, Arinix®).