Why Do Cats Sleep So Much? 為什么貓愛睡覺？

Jeff Wallenfeldt張寧

Cat person？ How many pictures of your cat sleeping have you got on your phone？ A lot， right？ They are so cute when they sleep...so cute. But then they are always asleep. Okay， not always， but a lot of the time. Why is that？

The truth is that cats sleep an average of 15 hours per day. Some of them stretch that toward 20 hours， especially older cats and kittens. Thats understandable. Whats wearing out the rest of them？

Cats are natural predators1. Their prey2 is quick and elusive3. Sneaking up and pouncing4—repeatedly—is undoubtedly exhausting. Cats in the wild work hard in order to meet their food needs， and expending that kind of physical effort requires a lot of recharging.

And they are not just predators， they are crepuscular5 predators， which means that the go lights come on for them at dawn and dusk during the twilight hours when their prey—rodents6 and birds—are equally active. The rest of the day， cats sleep， though that sleep is of two types.

About three fourths of their sleep is a shallow7， almost-waking rest. Cats doze in a kind of ready position. Their senses of smell and hearing are in the “on” mode. Ears occasionally twitch8. Peaceful but poised9， they are ready to react instantly： To pounce on prey or to swat and scratch the hell out of you for the temerity10 of petting them while they are sleeping. It usually lasts 15 to 30 minutes.

The other one fourth of the time， cats really sleep deeply. If it looks like they are dreaming when their paws tremble， it is because they probably are dreaming.

So what about my domestic， never-leaves-the-house cat？ Why is she always sleeping？ In a word： Heredity11. As a species， cats—whether they sleep on the street or on a sofa—are all hardwired12 to the same internal clock. That， and house cats also sleep when they are bored.

你是愛貓人士嗎？你的手機(jī)里有多少張貓睡覺的照片？很多，對(duì)吧？它們睡覺的時(shí)候很可愛……很可愛。但是它們總是睡著的。好吧，不說總是，但很多時(shí)候都是。為什么會(huì)這樣？

事實(shí)是貓平均每天睡15個(gè)小時(shí)。它們中的某一些把這個(gè)時(shí)間延長到了20個(gè)小時(shí)，特別是年齡更大的貓和小貓。這是可以理解的。但是什么讓其他的貓也精疲力竭呢？

貓是天生的捕食者。它們的獵物動(dòng)作又快又難以捉摸。悄悄靠近，再猛撲過去——反反復(fù)復(fù)地——這毫無疑問是累人的。野貓為了滿足食物的需要而努力捕食，而消耗了這種體力則要補(bǔ)充大量的精力。

它們不僅僅是捕食者，它們是晨昏性捕食者，這意味著，在天微亮的黎明和黃昏時(shí)分，當(dāng)它們的獵物——嚙齒動(dòng)物和鳥類——同樣活躍時(shí)，它們的出行信號(hào)燈就會(huì)亮起來。一天里的其余時(shí)間，貓會(huì)睡覺，不過它們的睡眠有兩種類型。

它們四分之三的睡眠是淺層的，幾乎是醒著的。貓以一種預(yù)備的姿勢打瞌睡，它們的嗅覺和聽覺處于“開啟”模式，耳朵偶爾會(huì)抽動(dòng)一下。它們平靜而沉著，隨時(shí)準(zhǔn)備做出反應(yīng)：猛撲獵物，或者因?yàn)槟阍谒鼈兯X的時(shí)候魯莽輕拍，而將你拍打抓撓得屁滾尿流。這種淺眠通常持續(xù)15到30分鐘。

另外四分之一的睡眠時(shí)間里，貓真的睡得很沉。如果它們的爪子抖動(dòng)看起來像在做夢，那是因?yàn)樗鼈兛赡芫褪窃谧鰤簟?/p>

那我家里從不離開屋子的貓呢？為什么它總是睡覺？簡言之，是因?yàn)檫z傳。作為一個(gè)物種，貓無論是在街上睡覺，還是在沙發(fā)上睡覺，都有同一個(gè)基本固定的生物鐘。因此，家貓也會(huì)在無聊的時(shí)候睡覺。

（英語原文選自：www.britannica.com）

【Notes】

1. predator [?????] n. 捕食者;食肉動(dòng)物 2. prey [?????] n. 獵物

3. elusive [?????] adj. 難懂的;難捉摸的 4. pounce [?????] vi. 突襲，猛撲

5. crepuscular [?????] adj. 黃昏的;拂曉的 6. rodent [?????] n. 嚙齒動(dòng)物

7. shallow [?????] adj. 淺的 8. twitch [?????] v. 抽動(dòng)

9. poised [?????] adj. 泰然自若的 10. temerity [?????] n. 魯莽，冒失

11. heredity [?????] n. 遺傳，遺傳性 12. hardwired [?????] adj. 基本固定的