The house is over 70 years old I am so I am assuming that it is seating
on some type of concreate blocks.The house is seating about 2 to 3 feet
above the ground. My neighbor's house built the same way. I don't know
if these blocks are solid or have hollow areas.


PCOpug wrote:

The sill plate is the top of the concrete block of the basement. The joist
boards are setting on the blocks.

If the sill plate is four inches up from ground level , then , it is very
difficult or unlikely termites would forage up that far. Usually mulch or
garden soil gets pile up high against the home , and above the sill plate.