Walls and Ceilings - Termite Damage Assessment in walls?

Q: Does anyone know a (relatively) non intrusive way to determine the extent of termite damage in walls? We'd like to have a plan in place to assess the termite problem before we make an offer... Read below for more info on the situation.

Background...My wife and I recently found a home we'd like to put an offer in on, but we just found out the house had/has a termite problem. The old owners kids were fixing it up before putting it up for sale and found 'evidence of termites' on the common wall between the garage and the house, just behind the fridge. They have since installed the bait stations, one of which has had a positive hit. This bait station is near the edge of the garage in the total opposite corner. I'm concerned since they first noticed damage in an interior wall and only did a visual inspection of the area where they first noticed them, that there may be more hidden damage from where they started eating their way in. Real estate inspection contracts generally say you can't get out of a sale contract without 'habitiability' issues. We'd like to have a plan in place to assess the termite problem before we make an offer...

Most states have a clause in real estate contracts that say [I think] that the sale is contingent on passing a termite inspection, ofcourse you are always free to sign off on no inspection but doubt you would in this case. I assume a good termite inspector is fairly thorough and well verse at examining hidden areas.