Since mold and mildew are a fungus, they do have somewhat of a smell. Black mold is really a living organism that has excrement. THey will eat off the surface material, and then simply become full and take care of business inside your home….
So to smell black mold can be quite nasty. Actually it just smells like a musty oder. Even a sock smell has been related to black mold and mildew.
So if you smell that musty odor, you may dirty socks laying around or black mold.