Synopsis Insects are small air-breathing arthropods of the class Insecta, consisting of six legs and multi-segmented body with two pairs of wings in most species. Insects comprise about five sixth of all known animal species, with a total of over one million named species.  They may be useful or harmful to man. Silkworm produces raw silk, which is, used by the world over in its refined form. Similarly, honeybee produces honey and wax, both of which are of great utility to man.  This modest work throws light on several other issues regarding insects, their anatomy, types, their uses and disadvantages, etc. It makes a very interesting reading.