An animal scale is a small, plate-like body covering on some vertebrate animals, like fish and reptiles, that provides protection, helps with moisture retention, and aids in movement. Scales vary by animal, with keratin-based scales on reptiles being rigid plates and chitin-based scales on butterflies providing coloration. Fish scales are bony and can be overlapping, like the cycloid and ctenoid scales, or spiny, as in placoid scales.
Types of Scales
Keratin Scales: Found on reptiles (like snakes and crocodiles) and are made of keratin, similar to fingernails.
Chitin Scales: Found on insects, such as butterflies and moths, and are made of chitin.