Elaine - I agree. I have no intention of baiting my entire yard. So I had nixed that idea.
I do use Andro fire ant bait and it does seem to work. I hadn't thought about going bad though. I have a package that is open now and will probably go bad before I am able to use it up. Drat! That stuff is not cheap either. But it works!
I do often think though that the ants just move to a new spot in my yard, I also have a carpenter ant problem. The ants are my biggest issue. I wished I had a large property so I could move bird feeders far away from the house. I believe that is what attracts the ants. I also have hummingbird feeders which is another problem with carpenter ants. They like sugar!