HELP! My rental has carpenter ants and I cant seem to get rid of them!

I have a rental in Boise Idaho that is infested with carpenter ants.  I have been through 2 exterminators who have put stuff in my crawl space, put stuff in my walls, put stuff in the house and outside the house.  My handyman found 6 nests and destroyed them and yet the keep coming back.  I am a wits end.  My tennant is about to move out and I don't blame her.  Carpenter ants are  something that must be disclosed when a house is sold and the market it terrible anyway.  I can't move another tennant in until the ants are gone.  I am also running out of money to deal with this problem or an empty rental.  How do I get rid of these pests?  Have they destroyed my house?