Animals
How Animals See the World Differently: UV, Infrared, and 16-Color Vision
The mantis shrimp has 16 types of photoreceptors. Pit vipers see heat. Many birds see ultraviolet colors invisible to humans and use them to choose mates. A dog's world is not black-and-white — it is dichromatic blue-yellow. Every animal lives inside a different visual universe shaped by what detecting which wavelengths was most useful for its ancestors. Here is what the science of animal vision actually reveals about perception.