动物是生物界中最庞大的一类，提到它们，谁都可以说出一长串的名字：猫、狗、虎、豹、秃鹫、蚂蚁、鲨鱼、蝴蝶、鹦鹉……可是你要说明白蝴蝶为什么是动物而不是植物，恐怕你就很难说清楚了。其实，动物有一个最大的特点，就是都要通过吃各自相应的食物来维持自己的生命。长颈鹿吃树上的叶子，狼吃比他弱小的兔子的肉，大鱼吃小鱼、小鱼吃虾米、虾米吃浮游生物（细菌、小型无脊椎动物和某些动物的幼体），正是因为如此，动物们才获取了生命活动所需要的能量，才能生长、发育和繁殖后代。所以说，动物是依靠掠夺食物来养活自己的，这也是动物和植物的根本区别。我们人类也是动物家族的一员，当然也要依靠食物才能生活下去。
Animals live everywhere.They roam the land.They burrow in the ground.They swim in the sea.They fly through the air.They creep，they leap，they soar，and they dive.A very few—including corals and barnacles—stay in one place.
Animals come in all sizes.The biggest animals are whales，which can be 100feet (30meters)long.The smallest animals can only be seen through a microscope.
Zoologists (scientists who study animals)have found more than 2million species (kinds)of animals.They think they have discovered only a small portion of all animals on Earth.
Several things make animals different from other living things.Unlike plants，animals cannot make their own food.Animals eat other living things—plants and other animals—to get energy.Animal bodies are made up of more than one cell，unlike bacteria and other life forms with only one cell.Cells are the building blocks of living things.Animals also have senses，such as eyes or ears，that tell them what is going on around them.
This drawing shows the parts of a lobster’s body.Lobsters are invertebrate animals，which don’t have spines.Lobsters are also crustaceans，a type of animal that has a hard outer shell.Most crustaceans live in water.
Gorillas are the largest of the apes.They live in the rain forests and mountains of tropical Africa.Unless attacked，gorillas are timid and peaceful.
What Kinds of Animals Are There？