Animals We can put animals into groups by studying their【1】. We also have to【2】the different parts of their bodies. Vertebrat

In our world of living things we have Plants, animals and people. Plants belong to a group called the Plant Kingdom while animals and people belong to the animal Kingdom.
   Look around you and you will see many different types of animals. Some animals are tiny while others are very large. Some animals are soft and long, while others are hard and rounded. Different types of animals which are alike in certain ways are put into groups. Let us find out how animals are put into groups.
   We can put animals into groups by studying their behaviour. We want to know how their bodies work, how they live, how they produce their young, how they find their food, what they eat, how long they live, and so on. We also have to examine the different parts of their bodies. When we examine them, here are a few questions we must ask ourselves: do they have scales, feathers or fur on their bodies? How many legs do they have? How many wings are there? Are there fins?
   But the first and most important question is: Do the animals have backbones or not? All animals with backbones are put into one big group called vertebrates. All animals without backbones go into another group called invertebrates.
   Invertebrates are animals which do not have backbones or other bones inside their bodies. Some have soft bodies and some have hard coverings which protect their bodies.
   Vertebrates are animals with backbones and bones inside their bodies. The bones help to support their bodies. There are five main groups of vertebrates—the fish, the amphibians, the reptiles, the birds and the mammals. Fish, amphibians and reptiles are known as cold blooded vertebrates. The blood of a warm-blooded vertebrate remains around the same temperature both on warm and cold days.
   Fish live in water and have fins which help them to swim; The body of a fish is made up of the head, the trunk and the tail. The tail ends in a tail fin. There are many different kinds of fish and they are of many different shaper and colours. Some fish are long and thin while others are flat and rounded. Most fish have bodies which are broad at the trunk region and narrow towards the head and tail.
   Frogs, toads, newts and salamanders are amphibians. All amphibians have thin skins which are usually wet and slimy. They have two pairs of legs. The toes of most amphibians have webs of skin between them. This allows them to swim well in water.
   The body of a frog or toad is made up of two parts head and the trunk. There is no neck or tail. Adult newts and salamanders have tails.
   Frogs and toads are important to human beings as they feed on insects. Some of these insects may be harmful to us. Toads produce poison from the skin for protection. Wash your hands after touching a toad.
   Reptiles live mainly on land but some live in water. They breathe through lungs and have dry scaly skins. Reptiles which live in water come to the water surface to breathe. Reptiles lay eggs with hard shells. Lizards, snakes and tortoises are reptiles which live mainly on land while crocodiles, alligators and turtles live in water. The body of a reptile such as the crocodile and lizard is made up of the head, the trunk and the tail. Most reptiles do not have necks. Many reptiles have four legs with toes. Turtles and tortoises have hard shells which protect their bodies. Snakes are different from the other reptiles because their bodies are very long and they have no legs. They move by gliding along the ground. Some snakes can also swim.
   Birds are animals with feathers on their bodies. They have many different types of feathers. Some are small and fluffy and others are long and flat. Feathers come in many different colours. Birds have no front legs but instead they have a pair of wings. They use their wings to fly. But some birds have wings, such as penguins and emus are small and stubby. These birds cannot fly. The body of a bird is made up of a head, a neck, a trunk and a tail. The mouth of a bird is in the form of a hard bill or beak. The shape of the bill depends on the type of food the bird eats. Some birds such as ducks, have flat bills for sieving small bits of food from the mud. Other birds such as eagles have sharp; pointed bills for catching small animals and tearing fish. Birds which search for frogs and worms in the mud, such as storks and flamingoes, have long pointed bills.
   Most mammals live on land but some such as whales and dolphins live in water. Some mammals such as bats have wings and can fly. Other mammals such as moles and rabbits burrow into the ground and live there. Mammals have hair on their bodies. Bears and dogs have very thick hair which is called fur. Human beings have little hair on most parts of their bodies but a lot on their heads. All mammals breathe through lungs. Even those which live in water have to come to the surface of the water to breathe. The young mammals grow in the bodies of their mothers. When they are old enough, they come out of their mothers’ bodies. When they come out, they are said to be born. The mother takes care of her new-born baby and feeds it with milk which is formed in her body. When the baby is older, he takes care of himself.