Medically reviewed by Marisa Garshick, MD Key Takeaways A callus is a hard and thick patch of skin caused by friction or pressure, often on hands or feet.Calluses can be treated with salicylic acid, a ...

In many animals, skin coloration and its patterns play a crucial role in camouflage, communication, or thermoregulation. In the corn snake, some morphs display red, yellow, or pink blotches, and their ...