4th Class Science Animals


Category : 4th Class




Living things can move, eat food and produce young ones. The process of producing young ones is called reproduction. Different animals reproduce by different methods. Some animals lay eggs and some give birth to young ones.


Egg Laying Animals

Animals like birds, reptiles, insects and amphibians lay eggs. An egg is an organic vessel in which an embryo begins to develop.



Birds lay eggs. Eggs have a hard, protective shell. Which contains a yellow yolk surrounded by white albumen. The yolk provides food to the chick growing inside it. The growing chick is called embryo. The parent bird sits on the egg to keep it warm. The chick breaks the shell and comes out when it has grown. This is called hatching.



Insects reproduce by laying eggs. Insects like butterfly and housefly have four stages in their life cycle i.e. egg, larva, pupa and adult. The egg is hatched into a larva. The young one looks different from the adult. The larva of a butterfly is known as caterpillar and that of a housefly is called a maggot. The larva first grows rapidly by eating the leaves. Then after sometime, it stops eating and forms a covering around itself called as cocoon. This is called the pupa. The larva changes into an adult inside the pupa and comes out of it after sometime.




Amphibians reproduce by laying eggs in water. The young frog which comes out of the egg is known as tadpole.



Fishes also reproduce by laying thousands of eggs in water. But only few eggs grow into baby fishes.




Reptiles lay eggs in the sand or rotting vegetation. They do not sit on the eggs to keep them warm. The sea makes them warm and the egg is hatched.

Animals Gluing Birth to Young Ones

Mammals are the animals which give birth to young ones and produce milk to feed them. They do not lay eggs. Dogs, monkeys, cats and human beings comes under the category of mammals. Bats are flying mammals. Whales and dolphins are also mammals living in water.



The home or natural environment of a living thing is known as habitat. All living beings changes themselves to survive in the natural world, for example, birds and insects can fly. This is called adaptation.


Classification of Animals on the Basis of Their Habitat

Animals are classified on the basis of the place where they live.


Aquatic Animals

Animals which live in water are called aquatic animals. Fishes live in water. They have fins for swimming in water. They have gills for breathing. Aquatic animals like dolphins and whales do not have gills. They have lungs for breathing for which they have to come to the surface of water. Birds like ducks have webbed feet which helps them to swim.



Frogs and toads are some of the animals which can live both in water and on land. They are called as amphibians.


Aerial Animals

Animals that can fly in the air are called aerial animals. Birds are aerial animals. They have light bones and wings to fly.




Terrestrial Animals

Animals that live on land are called terrestrial animals. Deer, zebra and lion are terrestrial animals. They have lungs for breathing. Desert animals like camels store fat in their humps. Animals like snakes do not have legs. They have scales on their bodies for crawling on the land.


Arboreal Animals

Animals that live mostly on the trees are called arboreal animals. They have claws and broad hip girdles for climbing. Examples are monkeys and squirrels are arboreal animals.




Some animals like bear and squirrel stores a lot of food in the form of fats under their skin during summers. In winters, when food is not there, they go on a sleep for a long time. This sleep is called hibernation.


Protection of Animals

Different animals protect themselves in different ways.

  • Rats and rabbits live in burrow in the soil to protect themselves from owls, eagles and foxes.
  • The huge size of whales and elephants protects them from other animals.
  • Animals like cheetah and deer run very fast to protect themselves.
  • Some animals like chameleon can change its colour to match to the surroundings. This is called camouflage. Animals like zebra, leopards have stripes on their body to make it difficult for other animals to notice them.


You need to login to perform this action.
You will be redirected in 3 sec spinner