Bones, stop growing after puberty and muscle and fat cells also stop dividing. But cartilage – that’s the plastic-like stuff in ears and noses – cartilage continues to grow until the day you die. Not only does cartilage grow, but the earlobes elongate from gravity. And that makes ears look even larger.
It is an irritant for mammals, including humans, and produces a sensation of burning in any tissue with which it comes into contact. Capsaicin and several related compounds are called capsaicinoids and are produced as secondary metabolites by chili peppers, probably as deterrents against certain mammals and fungi.