Molds are fungi that can be found both indoors and outdoors. Molds grow best in warm, damp, and humid conditions, and spread and reproduce by making spores. Mold growth is encouraged by warm and humid conditions. Indoors they can be found where humidity levels are high, such as basements, bathrooms, or kitchens. If there is mold growth in your home, you should clean up the mold and fix the water problem.