The answer to 'when to treat for ants' is that the best time to treat for ants is when you first notice them in your home. Ants are most active during the spring, summer, and fall months when the weather is warmer. At the first sign of an ant problem, it's important to take action to eliminate the colony and prevent them from becoming an ongoing issue.
Treating for ants early on, before the colony has a chance to grow, is the most effective way to get rid of them. Ants can reproduce quickly, so the sooner you address the problem, the easier it will be to get rid of them. Additionally, treating for ants during the warmer months when they are most active will be more successful than trying to treat during the winter when they are less active.