The answer to 'when to treat for fire ants' is that the best time to treat for fire ants is in the spring and fall when their activity is highest. Fire ants are most active when temperatures are between 70-85°F, so the ideal times to apply fire ant treatments are in the spring (March-May) and fall (September-November).
This is when fire ant mounds are most visible and the worker ants are actively foraging for food to bring back to the colony. Treating during these peak activity periods helps disrupt the fire ant life cycle and control their population more effectively.