To kill Fire Ants in their Mounds: DO NOT DISTURB MOUND PRIOR TO TREATMENT. Attach injector rod to can. While spraying, slowly drive rod into mound until resistance is met, which indicates the bottom of the nest has been reached. Spray for five seconds for each six inch diameter mound. For example, an eighteen inch diameter mound would require three separate injections around the mound. All mounds in the vicinity should be treated. For best results treatment should be made in the early morning or late evening when ants are least active.