Birds come under the class – vertebrates. Birds are basically warm blooded and they lay eggs.
Since they have a high body temperature, they utilize lots of energy and hence they needs to keep eating all the time.
The bodies of birds are covered with feathers which have mainly three functions. Feathers help them in their flight, helps them to have a regulated body temperature and in some cases is also for good display. Since the bones of birds are hollow and have air sacks, they are able to fly as it makes them lighter. Wings help them in their flight.
Birds are bipedal which means that they have two legs that are often covered with scales. Their beaks are hard and they have no teeth. It is estimated that there are more than 9000 different species of birds. Birds are carnivores, which means that most of the birds feed on flesh of other smaller animals like insects, fish, mice, etc. Very few birds live on plants and plant products like honey and nectar.
Birds are found in almost all parts of the world. They are found in freezing temperatures to dry hot desserts, at deep forests to low lying grasslands and so on. Some birds also migrate from one place to another to suit their type of climatic conditions. They are also found in many sizes. From a 60 mm long Bumble bee to a 2.5 meter high ostrich. Apart from sizes, they come in different shapes, colors who could adapt and camouflage themselves to the environment they live in. However, some birds have bright and vivid colors which help them to attract their mates. Though most of the birds fly, some birds do not fly. They are many that are flightless and have only small wings. Birds glide well and often use this technique when they land.
Birds make nests to lay their eggs and they look after their young ones till they are capable enough to fly on their own. The young ones would be fed on small insects or worms. Once the young ones are ready to fly, they are pushed away from the nests and made to be on their own.