Contrary to what one might think, simulation isn’t confined to human beings, nor is it necessarily something that is consciously created. Plants and animals use camouflage and other deceptive appearances in great profusion, which are essential tools in the struggle for survival. In many instances, these deceptive appearances consist only in an animal’s ability to walk with stealth or hide or remain completely still, to create the impression it isn’t there. As we discover in all those television nature documentaries, predators and prey are constantly slinking around in the underbrush, peering from behind obstructions and standing motionless, as they wait for the right moment to strike or flee from danger.