THE ABILITY to manipulate and control light is one of the foremost goals of modern optics. However, it is also something that nature perfected a long time ago. About 500 million years ago an evolutionary "big bang" took place, when animal life began to rapidly diversify. This so-called Cambrian explosion is thought to have been triggered when the manipulation of light began to influence the survival of many animals. When it comes to highly advanced optical systems, it seems there is no more experienced an engineer than nature itself.