Penguins are a kind of bird. They are different from other birds. They can’t fly! Most penguins live in cold place. They have thick layers（层） of fat on their bodies. These keep them warm, but they also make them too heavy to fly. Even though the penguins do not fly, their wings are very important. The penguins can swim through the ocean freely. Their wings help them move quickly in the water

The emperor penguins are the largest kind of penguin. Most emperor penguins grow to 45 inches tall and can weigh as much as 88 pounds! The wild emperor penguins only live in one place in the world, Antarctica（南极洲）. They are only animal that lives on land during the winter there.

Do you know how emperor penguins stay warm? Let me tell you. They huddle（挤作一团） together to stay warm. They huddle close together in a big circle. Each penguin takes turns standing in the middle of the warm circle. When that penguin gets warm, it move towards the outside of the circle. This lets another penguin go into the middle to get warm.

Cats don't seem very friendly. Unlike dogs, cats don't often play with people. However, a new study shows that cats like people just as much as dogs.

US researchers invited 117 cat owners to take a six-minute test. They walked into a new room with their pets. After two minutes, they left the room. After another two minutes, they came back. Two-thirds of the cats came to greet their owners right away when they came back. The cats then went back to look around the room, but still came back to their owners now and then.

The cats saw their owners as a source of security（安全的来源）in a new place. In the same test, 58% of dogs acted just like the cats.

"The more we find out about cats, the more we're seeing that they are social animals," said Kristyn Vitale, a researcher who worked on the study.

Fun facts about cats

Around 20 centimeters in length and with a 40-centimeter wingspan, this short-legged small bird is a common visitor of our beautiful Shenzhen.

With a white eye ring and a brown patch (斑) across the eye, the common sandpiper (鹬) is brown on the top of its body and white on the under parts. Its breast has a set of dark b rown patches and dark brown markings over the upper parts of the body.

Three special things about this small bird are its running speed, an unstoppable up-and-down movement of its tail and a constant (不间断的) nodding of its head.

It lives in northern areas from East Europe and Central Asia to Japan. During the winter months, it migrates (迁徙) to warmer locations in Africa and South Asia, including Shenzhen. It is common to see these beautiful birds along the margins (边缘) of rivers, lakes, ponds, and ocean shores. In Shenzhen Bay Park, they can be seen searching for food animals such as insects, spiders, frogs or small fish. When unable to find animal food sources, they feed on plants.

Another interesting fact about the common sandpiper is that they are very likely to return to the areas they visited previously. So over the years you will likely see them visiting the exact same locations during their migration.