22 Rats

Through all of human history, rats have been a curse and a plague to people. They estrange or spoil crops of grain and rice before they can be harvested ten times as many in storage. In India, where half of the people go hungry, rats will also attack birds and animals from frogs and chicks to geese and young calves. They have even destroyed dams and buildings by chewing on electrical wiring.

The most terrible destruction caused by rats, however, has come from the diseases they carry. In the fourteenth century, rats caused the death of one-third of the world's human population by transmitting bubonic plague. This dreadful outbreak, also called the Black Plague, ravaged Europe for years.

Ironically, rats, though quite different from rats of humans, have certain basic structural similarities. So thousands of specific breeds are used in research laboratories every year to test medicines that can possibly be used to prolong and improve human life. As might be expected, some laboratory rats are even used to test now procedures and methods for eliminating their cousins the wild rats.

22 老鼠

纵观人类历史，老鼠一直是人类的诅咒和灾祸。它们会破坏即将收割的谷物和水稻，储存中的粮食被破坏的量更是多达十倍。在有一半人口挨饿的印度，老鼠还会攻击鸟类和动物，从青蛙、小鸡到鹅和小牛犊都难逃其害。它们甚至会啃咬电线，破坏水坝和建筑。

然而，老鼠造成的最可怕破坏来自它们携带的疾病。14世纪，老鼠传播的黑死病导致全球三分之一的人口死亡。这场可怕的疫情也被称为“黑死病”，多年来肆虐欧洲。

具有讽刺意味的是，尽管老鼠和人类差异很大，但二者有某些基本的结构相似性。因此，每年有成千上万特定品种的老鼠被用于研究实验室，测试可能用于延长和改善人类寿命的药物。不出所料，一些实验鼠甚至被用来测试消灭它们的“近亲”野鼠的新程序和方法。