Since then I've knocked away some of the stucco along one outside wall at a different location (the garage) at ground level exposing the edge of the slab and found a few mud tubes, then looked inside the wall with a boroscope. I found more mube tubes along a couple of the 2x4's running along the point where they contact the presswood under the stucco.
I knocked away some of the drywall to get a closer look. I have no idea how old these mud tubes are, some extend higher than the area where I've opened the drywall, some just stop. The 2x4's I've checked so far seem solid when jabbing at them with a screwdriver. I don't see any of the classic "swiss cheese" bored into look that I've seen on some damaged wood. If the termites have done significant damage to the 2x4's, should it be obviously detectable from the outside? How do they operate, do they munch as they go or do they build a tube to a particular destination? As I check other walls with the boroscope, if I don't see mud tubes along the 2x4's can I assume they haven't gotten in at those points? I also plan to look up in the attic (or what passes for one here in Florida) to see what I can see there.
A local do-it-yourself pest control place told me that if you do a trench and fill termite treatment around the perimeter of the house, cutting the termites inside the house off from the outside, any termites inside will die out. Does this sound correct?
Thanks for all input.