Fine dirt accumulation along where basement floor meets wall. All concrete

Question

Just recently, there has been a slow accumulation of fine dirt at the base of my sub-basement. It has been cleaned away, then a week later it returns. It runs about eight feet along the base. Outside, about 9 feet above where the wall is (it's a driveway), there is also some dirt accumulation. Are there bugs digging behind the wall? I can't see any. Has anyone seen this?

Inside:

Outside:

Answer 1

You need to have an exterminator examine that. Leave it for them to see.

It could be termite frass (waste), or from some other insect like carpenter ants or beetles. Really needs a pro to look at it.