I have an 100 yr old town house that suffered termite damage over the years, at least one time majorly around 1985.. I don't have the cash to do a complete overhaul, but am doing things incrementally. such as replacing all the hardwood flooring in one floor of my house. I have an annual termite inspection and they were found once and treated. I last had a full treatment in July. My neighbors have the same experiences, so I'm not unique- we're near woods and a creek, so there's lots of wet wood nearby.
Generally it's an old house with lots of settling. It was also imperfectly rehabbed.
I have many cracks in the plaster and one, which happens to face an outside wall has a weird effect. If I seal the window and slam the door, little bits of termite-chewed wood come out. I did a visual inspection and do not see any holes in the old mortar (though repointing is in my future) and I held a wet finger to the crack and didn't feel any wind or cold air.
Has anyone seen this before?