We all think that what we see is reality, but most people don’t realize that everything we can see and the way we experience these things are limited by our senses and our culture that learns us how to interpret what we see. Everybody thinks they know what a rainbow looks like, but except for humans and apes there are few animals who see a rainbow exactly the same as we do. A large part of the mammals have only two different kinds of a colour cones in their eyes which makes it impossible for them to see the red colour spectrum, while most birds are blessed with an extra colour cone which enables them to see ultraviolet light a part of the spectrum which is invisible for us.