Found these strange dirt-like veins running up my basement wall. They crumble when touched but seem hollow inside. Do I have a leak or something else?

and Hidden Insects
Performing simple at-home tests can help confirm the presence of termite mud tubes. Gently break open a section of the tube with a screwdriver or similar tool. If it crumbles and reveals a hollow interior, this is a strong indication of termite activity.
Look for live termites within the tube. These insects are small, white to light continue reading …