The skunk20), which has a one-track mind, signals with his tail. If he whirls21) his hindquarters22) toward you, elevates that bushy tail and stamps his front feet, back away quickly, because he's ready to accurately shoot a fine spray, from two glands at the base of the tail, that will blind you and make you unfit for human society. The peaceful porcupine23) backs into battle, lashing its tail like a medieval mace24) and driving the barbed, loosely-attached quills25) into the face or body of its attacker. The possum26)'s long, muscular, naked tail is prehensile27) and is wrapped around a branch of a tree while feeding or used for carrying leaves to its nest. The flat trowel-shaped28) scaly29) tail of the beaver is not used as a trowel to carry mud but is used as a rudder30) and a powerful propeller31) while swimming, especially when towing branches. It is used as a prop32) when cutting trees and, in the water, to signal an alarm with a resounding hit.
Many animals, such as fishes, whales, birds and kangaroos, use their tails as an aid to locomotion. The sensitive tip on a mole33)'s tail enables it to travel backward as fast as forward in its tunnel. The jumping mouse is unsteady and may fall over after a leap if, by accident, it has lost part of its tremendously long tail. Most New World monkeys use their prehensile tails like a fifth leg or hand. A squirrel uses its bushy tail as a plane and rudder when leaping through the air, and for other important purposes. So we wonder what will happen to one we saw, recently, that had only the stump of its trademark.
没有尾巴的动物
人类没有尾巴，尽管在他们的脊柱底端有一些迹象。长臂猿及大型类人猿如黑猩猩、大猩猩、猩猩也是一样。原产于马恩岛的马恩岛猫和产于比利时的无尾短毛小黑犬完全没有尾巴。中南美洲的树獭及澳大利亚那可爱的贪睡小考拉熊虽然像猴子一样住在树上，但是也没有尾巴，也许是因为它们行动迟缓的缘故吧。在啮齿类动物里(它们中的许多种类都有相当长而粗壮的尾巴)，豚鼠以及南美洲的大水豚也都没有尾巴。
尾巴的功能
鳄鱼的尾巴可是有力的武器，它们用尾巴在水中行进、打击敌人、捕捉猎物。许多蜥蜴在被抓住尾巴时都会留下它们还在扭动的尾巴逃生，因为它们的尾巴可以很轻易地从脊柱中央断开。之后蜥蜴先生会再长出一条新尾巴。
一些动物的尾巴能表达丰富的含义。一起嬉耍时，狗会以摇尾巴来表示友好。我们的虎斑猫在感到愤怒或绷紧肌肉准备扑向猎物前，其尾巴的末端会来回抖动，就像狮子、老虎以及大多数猫科动物那样。弗吉尼亚驯鹿那短小而呈三角形的尾巴内侧有一块白色标志，当它飞奔着逃离危险时会竖起尾巴，把那块标记当作信号旗一般摇来晃去。而马、驴、斑马之类的牲畜则用它们的长尾巴准确地驱赶蚂蝇，嬉戏的牛群和受到惊吓的兽群则会在全速奔跑时将它们的尾巴高高竖起，颇为滑稽。
