The octopus spies a nice, tasty mantis shrimp. It swims over for a closer look at the small creature. Then--WHAM --the mantis shrimp strikes a nasty blow with its hammer-like forelimb. The octopus shrinks back, defeated. That wasn't such an easy meal after all . . .
In nature, good defenses can mean the difference between surviving a predator's attack and becoming its lunch. Some animals rely on sharp teeth and claws or camouflage. But...