...don't sign up for Terminix. We had a contract with them that they'd only come out in the months that there wasn't snow on the ground. Then after a couple of years apparently they didn't like doing that any more, and wanted to go to this quarterly deal...which costs more than having them come up the 5 or 6 times a year we wanted them (and if it's quarterly they'd only come twice but we'd pay a yearly fee).
I agree with Barb: do it yourself. We do the spray stuff, but no matter what you choose you need to do it regularly during the warmer/non-freezing months. We have the Carpenter Ants try to sneak into the house every year. In fact, when we bought the house it was infested and we had to have the whole place tented. It was crazy but necessary because in our case they were embedded into the soft foam insulation in the roof.