Mar 23, 2018 - 01:44 PM
The good news is that they normally don't reproduce in the winter either. This means that they are not in a "progressive" mode. The colony size tends to stay the same and they just sort of "maintain" in whatever capacity they can.
I would not recommend to spray anything unless you know exactly where the nest is and can kill the queens in the process. Sometimes they will nest in hollow doors, window boxes, window frames, etc. Treating these areas with pesticide can work, but only if you can hit the nest. Sort of like a "bullseye" approach. If you don't kill the nest, they will simply move away from the pesticide and can often split into 2 or more new colonies.
In most cases, it is better to wait until Spring when you can put the Ant Pros back outdoors and give the ants what they are looking for. Carpenter ants normally don't do much damage, they don't eat wood and are more of a nuisance than anything. Be sure to use fresh bait. Hope this helps.