You can usually tell that you have mold if you smell it or see it. Mold has a stale and musty odor, and even though all mold doesn’t have an odor, most do. Mold is also usually present in damp places or areas with a moisture issue. If you notice condensation or persistent moisture in areas with pipes, windows or other water sources, you may have mold there. One of the main indications of a mold problem is visible mold. Mold can appear as a furry, dark growth, as a black stain, or as black, white, orange, green or brown specks.