If you have a cat, it's likely that at some pointyou've seen it do this: while playing with your foot itsuddenly dropped to its side, latched on with itsfront claws and began a coordinated kicking motionwith both back legs.

如果你养猫，在某一时刻你可能会注意到它这样的举动：在脚边玩耍时，猫咪突然猛地下扑，用两只前爪抱住你的脚，两条后腿持续蹬踢。

The cat probably gave you a good four or fiveswats before letting go. From a human point of viewthis looks like great fun—a real rough-and-tumble kind of game. But where does it come from?

猫咪不给你来四五个猛击可能不会停手。对人来说看似很好玩，就像一场真正的混战游戏。但是这样的游戏是有由来的。

Before giving an answer, let's think for a second about the kind of thing we can learn evenfrom so commonplace an event. Housepets are not toys; although they are domesticated and,in the instance of cats, much smaller than their wild counterparts, it's a mistake to regard themas fundamentally different from wild animals. They share millions of years of evolutionaryhistory, and their behaviors--even playful ones--are in many cases behavior that was veryuseful in the wild.

在给出答案之前，花一秒钟来想想从这种最常见的游戏上能学到什么。家养宠物可不是玩具;尽管它们被驯服了，并且比野生的同类体积小许多，但是拿猫来说，如果你认为家猫与野猫有本质的区别，那就大错特错了。它们有着上百万年相同的进化历史。家猫的一些行为，即使很有趣，但对野猫来说是有很用的。

So, think again about that front-claw grab connected with a back-claw kick that your catdoes from time to time. You may see it in a new light when you realize that the cat is executinga very effective device for killing prey or enemies: hold the other animal's stomach in placewhile you disembowel it.

所以，再想想你家猫咪那一次又一次，前爪抱后爪踢的动作。以另一种观点来看待的话，你或许会发现猫咪是在执行一种很有效的能杀死猎物或敌人的动作：前爪按住其它动物的胃部，后爪钩出内脏。

Of course, that doesn't mean your cat is really trying to hurt you; but it does show us thatplayful behavior in animals --and, oftentimes, in humans--is not simply nonsense. In manycases it is a practice run for learning more useful skills--even deadly ones.

当然，这并不表示你的猫咪是在伤害你;但也证明动物之间，或者动物与人之间的一些顽皮行为并不是无用的。在许多情况下，这是在演习更有用的生存本领，即使是致命的本领。