Mold is everywhere—it grows from microscopic airborne spores, and once those land on something, mold grows and can do a lot of damage to the materials it's on. Out in the woods and fields, mold's job is to break down organic materials and return them to the earth as nutrients. Unfortunately, mold doesn't discriminate between a fallen tree branch and a living room wall. Its job is to break down whatever it's growing on, and it's very good at doing this. Mold thrives in moist,