8 A2 swing, slither, swim

CHAPTER 1 How Many ways Do Animals Move? ANIMALS MOVE TO FIND FOOD AND STAY SAFE. SOME ANIMALS USE THEIR LEGS; SOME USE THEIR ARMS; AND SOME USE THEIR WHOLE BODIES TO MOVE. THERE ARE MANY KINDS OF ANIMAL LOCOMOTION. Many animals move on two or more legs. A penguin walks on two legs. A horse runs on four legs. A grasshopper hops on six legs. A centipede walks on many small legs, and it can even run if there is danger. Animals can also move quickly with their arms. A monkey uses its arms to climb trees and look for food. Birds use their wings to fly. Fish can swim thanks to their fins.

What about animals that don't use their arms and legs to move? How do they move? Well, a snake doesn't have arms or legs, but it can move very fast. It uses its whole body. A pangolin has arms and legs, but sometimes it doesn't use them to move. If the pangolin is in danger, it becomes a ball and rolls away to be safe. Isn't it amazing how many kinds of locomotion there are? Each kind of animal has its own special way of moving.

CHAPTER 2 Legs NATURE SAYS "MOVE IT OR LOSE IT!" BUT LOSE WHAT? YOUR LIFE! Animals often have to move fast to get away from danger. If they can run fast, they can get away and be safe. Is it better to have four legs or two when you want to run away from danger? Horses run with four legs and they can run very fast. However, their legs are very slim, and they break easily. Also, horses get most of the sleep that they need standing up. So if a horse breaks its leg, this makes it very difficult for the leg to get better.

Penguins have two legs, but they can't run fast. In one hour, penguins can only walk about three kilometers across the ice of Antarctica. Penguins are birds, but they can't fly! But luckily for penguins, they can swim very well to get away from danger. Like ducks, penguins have wide feet. This helps them swim fast. Some penguins can swim at a speed of 24 kilometers an hour! Ostriches are the largest and heaviest birds in the world. Like penguins, ostriches cannot fly, but they can walk and run fast. In fact, they can run as fast as 70 kilometers an hour. Ostriches' legs are the longest of all birds, and they are very strong. Believe it or not, an ostrich can kill a person with one kick!

Kangaroos also have powerful legs. Their big back feet and long back legs are much larger and more powerful than their front feet and legs. This means that kangaroos can travel very fast, but they don't run. They hop. Kangaroos usually hop at speeds of 25—48 kilometers an hour. Grasshoppers, like all insects, have six legs. They use their powerful back legs to hop very far. A grasshopper that is 2.5 centimeters long can hop 50 centimeters: That's twenty times its size! So, the grasshopper can move away from danger quickly. Grasshoppers also use their legs to make music! This tells other grasshoppers that danger is near.

Centipedes have even more legs than insects do. The word centipede means "one hundred feet," but some centipedes have only thirty feet, whereas others have three hundred! Their many legs help them move away from danger. Millipedes have more legs than centipedes, but millipedes move slowly because they have short legs that can't go very far. Centipedes also have two larger, special legs that they use to catch and eat their food— like teeth! All of the animals in this chapter use their legs for locomotion. Some animals have more legs than others, but more does not always mean better. Each animal has its special way of moving to be safe.