When you see a cockroach or a bed-bug your first reaction is one of disgust and that is immediately, followed by a desire to exterminate the offensive creature. Later, in the garden, you see a butterfly or a dragonfly, and you are filled with admiration at its beauty and grace. Man’s feelings towards insects are ambivalent. He realizes that some of them for example, flies and cockroaches arc threats to health. Mosquitoes and tsetse flies have in the past sapped the vitality of entire tribes or nations. Other insects are destructive and cause enormous losses. Such arc locusts, which can wipe out whole areas of crops in minutes; and termites, whose often insidious ravages, unless checked at an early stage, can end in the destructing of entire rows of houses.
Yet men’s ways of living may undergo radical changes if certain species of insects were to become extinct. Bees, for example, pollinate the flowers of many plants which are food sources. In the past, honey was the only sweetening agent known to man in some remote parts of the world. Ants, although they bite and contaminate man’s food are useful scavengers which consume waste material that would otherwise pollute the environment. Entomologists who have studied insect fossils believe them to have inhabited the earth for nearly 400 million years. Insects live in large numbers almost everywhere in the world, from the hottest deserts and the deepest caves to the peaks of-high mountains and even the snows of the polar caps.
Some insect communities are complex in organizations, prompting men to believe that they possess an ordered intelligence. But such organized behaviour is clearly not due to developed brains. If we have to compare them to humans, bee and ant groups behave like extreme totalitarian societies. Each bee or ant seems to have a determined role to play instinctively and does so without deviation. The word “instinct” is often applied to insect behaviour. But some insect behaviour appears so clear that one tends to think that some sort of intelligence is at work. For example, the worker bee, upon relating to the hive after having found a new source of nectar, communicates his discovery by a kind of dance which tells other bees the direction and distance away of the nectar.
