Optimum foraging by red imported fire ants usually occurs when the soil is moist, and the temperature is between 65 and 85 degrees Fahrenheit under sunny skies. Baits should not be applied if precipitation is expected within 24 hours of treatment or the bait may be ruined. If conditions are not favorable for a bait application, then treatment should be delayed. While bait applications can be made any time of the year that conditions are favorable, the Texas Agricultural Extension Service promotes the application of baits in the fall months, typically September and October. Bait applications in the fall are advantageous for several reasons.
Baits take several weeks to months before the effects become evident.
Applying bait in the fall reduces the chance of problem encounters with fire ant mounds because both people and the ants are not as active outside as they would be in spring months. By the time spring arrives, ant populations should be fully suppressed. This is not to say that bait must only be applied in the fall. About two percent of the human population can react to stings enough to need medical attention, with a smaller percentage having life-threatening reactions. Red imported fire ants are a serious health risk because they endanger troops near foxholes and sandbags.