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Theyre cute， theyre furry and sometimes they like to bring you dead birds or rats. Thats right， were talking cats here.

The fact is that free-roaming1 house cats are dangerous to our environment. Studies have shown that even well-fed cats kill wildlife when given a chance. Not only that， but an especially skilled cat can kill up to one thousand animals per year.

Even if your own cat isnt a skilled killer， with millions of cats on the loose2 all over the world， even ten animals per cat adds up quickly. Whats more， only some of these kills are pests like rats. Others are birds and mammals3.

Cats in the United States kill up to 3.7 billion birds every year and as many as 20 billion small mammals. Cats also hurt animals like hawks4 and weasels5 by stealing their food.

This problem is becoming more serious by the fact that people take pretty good care of their cats. This means that disease and competition for food dont affect the cat population.

Cats are born hunters—theyll hunt for pleasure even if theyre not hungry. So what can you do to stop them？

Do what you can to keep your cats indoors， no matter how wistfully6 they stare out the window. Also， do your share to keep the population under control.

Cats kill a lot of wild birds and other animals. And dont other pets kills wild animals？

Yes， they do. In fact， after cats， one of the main killers harming wildlife is none other than mans best friend—dogs.

And many cats roam free while dogs are either kept on leashes7 or in yards. So how can dogs possibly do as much damage as cats？

Well， in the United States， dogs dont kill as many animals as cats. But consider that in many other countries dogs are not kept in yards. Experts estimate8 that around 75% of dogs around the world are free. And when they are free， they are also killers.

For example， in the 1980s researchers found that a single stray9 dog in New Zealand killed as many as 500 birds called Kiwis. In 2006， a small pack of stray dogs on Viwa Island in the South Pacific came close to wiping out a species10 of ground frog.

So， in fact， the point is not the killer cats or dogs but how human beings keep the balance of nature.

可愛的，毛茸茸的，有時(shí)會(huì)給你捎來死去的小鳥和老鼠的小家伙——對(duì)啦，我們正在談?wù)摰木褪秦堖洹?/p>

事實(shí)上，整天在外頭閑逛的家貓對(duì)我們的環(huán)境很危險(xiǎn)。研究表明，若有機(jī)會(huì)，食物豐足的家貓也會(huì)獵殺野生動(dòng)物。不僅如此，那些狩獵技術(shù)格外嫻熟的貓咪甚至可以在一年里殺死多達(dá)一千只動(dòng)物。

即便你家的貓咪并不是個(gè)技術(shù)精湛的殺手，但當(dāng)數(shù)百萬只貓咪在世界各地游蕩時(shí)，就算一只貓咪只殺死十只動(dòng)物，數(shù)量累積的速度也將非?？?。而且只有一部分被殺死的動(dòng)物，比如耗子，是有害的，余下的受害者則是鳥類和其他哺乳動(dòng)物。

在美國，貓每年殺害37億只鳥類和200億只小型哺乳動(dòng)物。貓咪還會(huì)搶奪其他動(dòng)物，比如老鷹和鼬鼠的食物，威脅到它們的生存。

人們對(duì)貓咪的精心照料導(dǎo)致問題更加嚴(yán)重。這意味著疾病以及對(duì)食物的爭奪都不會(huì)影響到貓咪的數(shù)量。

然而貓咪卻是天生的獵食者——它們甚至?xí)谑澄锍渥愕那闆r下為享受樂趣而捕獵。那么，你能做些什么來阻止它們呢？

無論貓咪望向窗外的眼神有多么充滿渴望，你都要盡一切可能讓它們呆在家里。此外，要控制好貓咪的數(shù)量。

貓會(huì)殺死許多野生鳥類和其它動(dòng)物。但是其它寵物就不會(huì)殺害動(dòng)物嗎？

是的，其它寵物也會(huì)。事實(shí)上，緊隨貓之后，殺死其它野生動(dòng)物的主犯正是人類最好的朋友——狗。

許多貓行動(dòng)自由，而狗卻被拴著或是關(guān)在院子中。這樣，狗為什么能與貓?jiān)斐赏瑯哟蟮钠茐哪兀?/p>

在美國，狗殺死的動(dòng)物沒有貓殺的多。但在其他許多國家，狗沒有被圈養(yǎng)在院子里。專家們估計(jì)全球大約75%的狗是自由的。一旦行動(dòng)自由，狗也是殺手。

比如，在20世紀(jì)80年代，研究人員發(fā)現(xiàn)在新西蘭一只流浪狗殺害了多達(dá)500只名為幾維的鳥。2006年，在南太平洋維瓦島上，一小群流浪狗幾乎讓一種陸地蛙滅絕。

因此，實(shí)際上問題的關(guān)鍵不在于殺手貓咪或者狗，而在于人類如何保持自然的平衡。