S. atra is black, shiny, and slimy. This mold is most commonly found on straw, hay, and livestock feed. This mold only grows on high cellulose, low-nitrogen materials like wood, paper, cardboard, and building materials like sheetrock that have gotten wet. In buildings, this mold lives in environments of high humidity and ongoing water damage. This mold may be present in homes that flooded or had plumbing, roof, or sewer leaks. S. atra is not common in homes. It is not the common mold found on shower tiles or along window seals. However, any molds found in large populations in buildings and homes may cause health problems to some people.