Pigs do it. Mice do it. Dogs also do it. Kangaroos? No, not so much. Why do some animals shake (抖动)? The short answer is because they are wet. But there's actually more to it than that-a lot more.
In an article, Andrew Dickerson and others took a look at this strange problem. The scientists wrote down the shaking of 33 animals, of them are five kinds of dogs.
It shows that mammals(哺乳动物)can keep stronger by doing their cute little shakes If they do not shake, animals would have to use up to 20% of their daily energy simply for staying dry. And nearly all furry(毛皮的) mammals shake to help themselves keep dry.
Those animals that are similar to kangaroos shake only part of their body. They usually live in dry places where keeping dry isn't very hard. But not all animals shake in the same way. Also some shake less often than others. Smaller animals seem to shake more quickly, 30 shakes per second for a mouse, while bears, tigers and big dogs only about four.
In an interesting finding, Dickerson and his team have shown that these animals do the job as well as possible. In each example, the animals shake off about 70% of water in a few seconds. This should all be great to people. It takes us not seconds but minutes to dry our hair.
