A species of viperine snake, which is not poisonous, has evolved three ways to protect itself against predators. The first is camouflage, so that it gets ‘lost’ against its background. However, its camouflage is very similar to that of the poisonous adder, which leads to the second method: mimicry. If a predator sees through its camouflage, it exploits the resemblance to an adder by behaving like an adder. But if this doesn't work either, for example when the predator is a crow, which kills adders, it adopts the third strategy. It flips about like a demented rope, and then it arranges itself on the ground to look for all the world like a dead snake, lying on its back in the dust at an awkward angle, with a vaguely bloated look ….

However, if it is now turned on to its front, it promptly and energetically flings itself back into its ‘dead snake’ pose.