Molds

Molds (fungi or mildew) are tiny parasites that live on decaying plant or animal matter. They grow almost everywhere—on soil, wood, fabrics, and foods. Some are cultured commercially for the production of drugs such as penicillin. Some are edible, such as yeast and mushrooms, and many are used to produce certain foods: cheese, soy sauce, yogurt, wine, and beer, for example.

Molds thrive in warm, moist darkness. Dryness is their enemy. They reproduce by forming spores (asexual reproduc­tive cells) and sending them into the air all year round, but mainly in the warmer months. The spores do best in wet cli­mates and, like pollen, can be carried great distances by the wind.