Introduction
Like other arthropods, insects are animals with jointed legs and a segmented body. Insects are unique among arthropods in having a body with three distinct regions: head, thorax and abdomen. Insects are the largest group of animals on earth. In fact, there are more different kinds of insects than all other species of animals combined. Over one million species of insects have been identified, but some scientists believe that this may be only a small fraction yet to be discovered.
Less than one percent of insects are harmful to humans, and some cause major damage to food crops. Without insects, however, we would not have the insect-pollinated foods that we eat every day. In fact, insects perform so many other important functions - like breaking down decaying matter, keeping soil healthy and serving as a food source for so many other animals in the food chain - that we might not be able to survive without insects.
