These miniature marvels are unbelievably intertwined in our cultures and everyday living. Each of these alien creatures has a fascinating story to tell. Insects have existed on this planet since time immemorial, and now constitute over 80%, the largest group of known animals. About a million different insect species are known and it is thought that millions more have been undiscovered among us. Insects are among the class of the Arthropoda. The insects inhabit almost all habitats on this earth, with the exception of the oceans. The greatest biodiversity exists in the tropics.