Can you catch one or two and freeze them or dunk them in alcohol (rubbing or vodka) or something to make them hold still and pose for a better photo? They do have that termite vibe....what general part of the world are you in?

I'm in south Louisiana. After posting this, we found they were coming from our front porch area. Now that it's daytime, they are all gone, and I see dead ones in the house. I'll try to take a better picture.

Termite was my impression also.