When you close your eyes and need to rest, sleep is just the very best. Sleep helps your body grow and stay healthy. However, in the animal world, it seems that some animals don’t need much sleep.

Giraffes usually sleep, although not for a long time. In places like zoos, giraffes have been known to sleep for between four and five hours, mostly at night. During sleep, the animal may lie down or stay standing. Standing sleep is more common among older giraffes. In the wild, however, the animals almost never sleep for longer than five minutes at a time. More often, they sleep fully standing and their eyes are half-open so they can see an enemy getting close.

Deer (鹿) do not sleep much during the day or the night. In fact, the night is a dangerous time for the animal to sleep because some of their enemies look for food at night. However, deer try their best to sleep for three to four hours. Even when sleeping, they have to be careful so that they do not become food for their enemies.

The Alpine Swift (雨燕) is a bird that lives in places from southern Europe all the way to the Himalayas. These birds spend a lot of their time flying to the warmer places and all the way to the south of Africa. The birds may spend up to 200 days flying during their journey. These birds sleep while they fly. The Alpine Swifts are able to sleep with one side of their brain while the other side pays much attention to flying and finding enemies.

Dolphins (海豚) usually go to sleep with only one side of their brain so that they use the other side of their brain for swimming and to watch out for enemies. Some dolphins do not go to sleep in the first month of their lives. Instead, they rest by pushing their bodies against their mothers so that they do not drown (淹死).Mothers need to make sure that they do not go to sleep. That is why mother dolphins are able to go for at least a month without sleeping.

Bees pollinate（给……授粉）plants in nature. With their hard work, plants are able to produce fruits and vegetables. 【小题1】 In Europe, there are about 800 kinds of bees in the wild. But one fifth of them may completely disappear from the earth.

【小题2】 Scientists have found a few possible reasons.

Many honeybees lost their lives because of hornets（大黄蜂）from other areas. Recently, scientists in Europe have been worried about a kind of hornet called the Asian Hornet. Such hornets are unkind and strong. 【小题3】

The use of chemicals is another cause. 【小题4】 Because of that, chemicals stay on plants for long. They do great harm to them while bees are pollinating the plants.

The greenhouse effect is also a main reason. Many bees can only live in certain areas. As the world’s temperature continues to rise, the areas for bees to live in become fewer and fewer.

Most bees are important to nature. 【小题5】

Even the smallest creatures(生物) have special ways to protect themselves. Spiders bite. Bees sting. Stink bugs(臭虫) stink.

Unlike spiders and bees, stink bugs do not hurt other creatures when they protect themselves. When a stink bug is in danger, it gives off a mix of chemicals(化学物质). It has a very bad odor. When animals like mice or birds smell the odor, they do not want to eat the stink bug. Also, when a stink bug releases its odor, other stink bugs nearby know that there is trouble. They will run away from the danger.

Although stink bugs do not bite or sting, they are still bad to human beings. Because stink bugs eat fruits and vegetables like beans and berries, they can damage a farmer’s crops(庄稼). When winter comes, stink bugs often move into people’s houses. It is very difficult to get stink bugs out of a house. It can be dangerous to use insect poison(杀虫剂) to kill stink bugs inside your house. Also, if you kill a stink bug in your house, your house will not smell very good.

One way you can try to keep stink bugs out of your house is to use their own defense(防卫) against them. Since the bug’s stink is a warning to other stink bugs, you can try squishing(挤压) a lot of stink bugs outside your house. This way, other stink bugs will smell the odor and know that your house is not where they want to be.