I don't know anything about termites personally, but you should be aware that a new method for eradicating termites was developed by Dr. Myles of the University of Toronto Forestry Department for the City of Toronto's Urban Entomology Program. Basically, Dr. Tim Myles has developed a very simple but highly effective method of eliminating termites that uses their instinct to "groom" each other that can be used to spread a lethal but slow working insecticide throughout the termite population in anything from a single family home to an entire city neighborhood or district. Right now the program is using volunteers to rid entire sections of the suburbs around Toronto of termites, and it can also be applied to a single house as well.
In a nutshell, the process involves placing or burying metal cans with corrugated cardboard inside them in areas where you've reason to believe that there are termites. Termites love cardboard, and after feasting on it, they will return to their colony to tell the other termites where to find cardboard. You simply monitor the "trap" until you find termites in it. Then, you put those termites into a Pyrex pan with tall sides that the termites can't escape from and dab them with a slow working insecticide (which I think is called "Sulfluramid") and put the termites back into the trap with new cardboard in it.
When returned to it's original location, the treated termites will return to their colony to tell the other termites where to find cardboard. The treated termites will be "groomed" by the other termites who will instinctively lick the insecticide off the treated termites. As each group of treated termites returns to the colony, they are groomed and more and more insecticide is distributed to the termites in the colony. You keep trapping, treating and releasing until your traps are consistantly empty of termites, which means there's no more live termites who know where to find cardboard.
There used to be an entire website devoted entirely to the Trap, Treat and Release method but I can't seem to find that web page now.
Buy yourself a $5 long distance phone card and phone Dr. Tim Myles to find out more about the program and where you can get more information on the insecticide to use and the procedure: