What is a "scale"?

A scale is a small, overlapping, bony, or keratinous structure covering many animals' bodies, such as fish, reptiles, and certain mammals. They provide a protective outer layer that serves various functions. In fish, scales help reduce friction in the water, aiding in streamlined movement and reducing energy expenditure. They also provide a barrier against physical injuries and pathogens. Reptiles, such as snakes and lizards, have scales that provide protection from external elements, regulate body temperature, and assist in locomotion by providing traction. Scales in mammals, like pangolins and armadillos, are made of keratin and form tough, armor-like coverings for defense against predators. The diversity of scales across different species reflects their adaptability and importance in the animal kingdom, playing essential roles in locomotion, protection, and environmental adaptation.