Aspergillus niger is a common species of fungi that forms as black mold on objects and food. This fungus is primarily found in soil, and prolonged exposure can cause painful, fungal ear infections as well as a severe lung disease known as aspergillosis. Aspergillus niger spores can easily migrate through the air and form deposits on surfaces. Active spores can then be transported by touch, resulting in increased exposure which may put others at risk. Black mold deposits are often observed inside walls and on bathroom surfaces.