As a matter of fact, people usually sing because they do like music or because they feel happy(1)___________________________When a bird sings however, its song usually means much more than a bird is in a good temper. Birds have a variety of reasons for singing. They sing to give information and their songs are their languages. (2)___________________ They sing when they want to attract a female bird. It is their special way of saying that they are looking for a wife and any other birds who are interested can respond to his song. Birds also sing to tell other birds to keep away. To a bird, his tree or even a branch of the tree is his home. He does not want strangers come near to his home. So he sings in order to warn them away. (3)_____________________________ For example, some birds dance, spread out their tails or make other kinds of signs. There is also a special kind of bird which builds a small garden of shells and flowers to attract a female bird’s attention.