black walnut

Mold is an opportunistic fungal microorganism that needs moisture, darkness, and decomposing organic material (nutrients) to survive. The spores (reproductive agents) are most-often carried on air currents, floating in and out of human living spaces by the thousands (sometimes millions). In other cases, the spores land on a person or animal and are then transferred from one possible habitat to another. As long as there is a dark, damp, and warm place with spoiling food, dead insects, wood, or even dust (which originates from human skin cells), mold can grow just about anywhere it lands.