These adaptable birds traditionally nest in the burrows of prairie dogs.

这些适应了新环境的鸟儿原本将巢穴驻在草原犬鼠的洞穴中。

At 12 meters, we can find the deepest burrows dug by animals — the Nile crocodile.

地表以下12米深的地方，我们可以找到动物能挖掘的最深洞穴——尼罗河鳄鱼挖的。

That length comes in handy for hunting in burrows.

这个长度在洞穴狩猎时能够派上用场。

Say, for example, that a muskrat burrows herself a den in one bank of a stream.

比如说，麝鼠会在溪流的一岸给自己挖个洞穴。

They're basically giant grumpy squirrels who dig burrows underground.

他们基本上就是体型巨大、脾气暴躁且会挖地洞的松鼠。

Some of the smaller species, like thescelosaurs and leptoceratops, could have burrowed underground and hibernated.

像奇异龙和纤角龙等小恐龙会挖个地洞冬眠。

Giant tortoises, however, can't burrow. And they sleep above ground.

然而，巨型陆龟却没有挖掘的技能。他们在地上冬眠。

On the exposed plateau, pikas never stray far from their burrows.

在毫无遮挡的草原上，鼠兔从不敢远离自己的洞穴。

Small mammals most likely burrowed underground.

小型哺乳动物很可能潜藏在地底。

And they've been found using gopher tortoise burrows in South Florida.

它们是在佛罗里达州南部的地鼠龟洞中被发现的。