Moles are growths on the skin that are usually brown or black. They are formed by clusters of melanocytes, the pigmented cells responsible for your skin color. Moles typically appear during the first 30 years of life, can be flat or raised, and can darken with sun exposure, puberty, or pregnancy. If a mole appears suspicious to the provider, they will likely recommend a biopsy. If a mole is determined to be “atypical,” the provider may recommend an additional procedure (excision) to remove a bit more of the tissue.