科技資訊:自我保護之凍結的一瞬間

Suppose you are an animal. Well, actually, you are an animal, but suppose you’re another kind of animal, maybe something small that might make a tasty snack for a larger predator. You’re walking along one day when you see a big dog. What do you do?

假設你是一隻動物。額，你其實本來就是一隻動物。但假設你是另外一種動物，也許是一種可以被食肉動物當成可口點心的小動物。如果有一天你在獨自散步時看到一條大狗，你會怎麼辦？

Well, depending on what kind of animal you are, you have different options. A skunk can spray a noxious liquid that will repel predators, a cat can make its hair stand on end so that it seems larger than it is, or some animals, such as opossums, may pretend to be dead already.

好吧，這取決於你是哪種動物，你有不同的選擇。一隻臭鼬可以釋放毒液擊退捕食者，一隻貓可以讓它的毛髮倒豎起來，讓它看起來比往常更大，還有一些動物，比如負鼠，也許早已裝死躺在地上了。

There’s another strategy all these animals have, though. You’ve seen it before, but maybe never thought about it. They can freeze.

其實這些動物還有另外一條策略，雖然你可能以前見過，但也許你從來沒想到過。它們可以凍結。

When a squirrel or a rabbit or a chipmunk freezes, it can remain almost entirely motionless for minutes at a time. Try it yourself. Whatever position you’re in right now, move nothing at all for the next minute. It’s not so easy!

當一隻松鼠，兔子或花栗鼠凍結時，它可以一次保持完全靜止不動達數分鐘之久。你自己試試。不管你現在是什麼姿勢，在下一分鐘內保持一動也不動。這可沒那麼簡單！

The reason an ability to freeze works as a defense is that a predator’s attack behavior may actually be triggered by motion. A frog, for example, will literally starve to death in a box full of dead flies. Pass one of those flies in front of its eyes on a little string, though, and it will automatically gulp it down.

凍結能作爲一種防禦的手段，其原因在於一個食肉動物的攻擊行爲可能只是由運動而引起。舉例來說，一隻青蛙，會在裝滿死蒼蠅的盒子裏活活餓死。用一根線綁住其中一隻從它眼前經過，它就會不假思索的把蒼蠅吞下去。

The response to freeze is completely hard-wired, so freezing shows us something about both predator and prey. Evolution has caused the freeze strategy to come into existence precisely because it fits in with the way the visual systems of predators operate.

對凍結的反應是動物與生俱來的，所以凍結給我們展現的是捕食者和被捕食者雙方的特性。進化已使得凍結策略應運而生，因爲它適應了捕食者視覺系統的運轉方式。