
thumb|upright=1.35|Many animals, such as this grey reef shark, are countershaded. thumb|Illustration from the artist Abbot Thayer's 1909 book on camouflage of a Luna [[caterpillar Actias lunaa) in position b) inverted.]]
thumb|upright=1.35|Many animals, such as this grey reef shark, are countershaded. thumb|Illustration from the artist Abbot Thayer's 1909 book on camouflage of a Luna [[caterpillar Actias lunaa) in position b) inverted.]]
Countershading, or '''Thayer's law''', is a method of camouflage in which an animal's coloration is darker on the top or upper side and lighter on the underside of the body. This pattern is found in many species of mammals, reptiles, birds, fish, and insects, both in predators and in prey.
Discovered by embedding cosine similarity (sentence-transformers MiniLM, 384-dim).