Write a paragraph on any one of the following outlines in about $100$ words.
Insects - two main kinds - useful, harmful - useful: bees silkworms - honey and silk - food and clothing - harmful: locusts, mosquitoes - locusts eat growing plants - destroy crops - mosquitoes cause malaria - millions die - neither harmful nor useful: butterfly, ladybird - pretty, colourful.

Insects are of two main kinds. They are harmful and useful insects. Bees and silkworms give us honey and silk respectively which are useful for food and clothing. Harmful insects like locusts eat growing plants and destroy crops. Mosquitoes cause malaria and millions die due to this deadly disease. There are other insects like butterfly, lady bird that are pretty and colourful but they are neither harmful nor useful.
Moral: Nature is the best teacher.