Moles or melanocytic nevus occur when melanocytes or cells in the skin grow in a cluster. The environment and genetics may also play an important role in its development. They may darken after exposure to the sun, during the teen years, and during pregnancy. There are several types of moles such as congenital nevi or dysplastic nevi. There are no new treatment that prevent them from occurring. Discuss with your dermatologist the different methods of mole removal and decide on which method is best for you. Take care and best regards.