What are freckles? How It Works How to Tell the Difference Between Freckles, Sunspots, and Moles Mole vs Freckle How to Tell & When to Get Checked Freckles develop when specific skin cells produce extra melanin in response to sunlight. When ultraviolet rays reach the skin, melanocytes release melanin to protect deeper layers from damage. In some people, certain The Little Freckle That Was.Melanoma Maury County Living Melanotan II: Tanning, Sexual Health Benefits, & Safety Concerns