If nature were left to her own, plants and animals would flourish. But, since mankind's needs increase constantly, insects and some animals have come to be know as pests instead of a part of nature. They are sometimes called bugs, pests, and creepy crawlers to name a few. Chemical poison repellents were invented to control pests. While they do their job and control pests, sometimes they control beneficial insects also.
Some pests do beneficial work such as pollinate fruits, vegetables and flowers.
Some break down organic matter and still others kill pests. When chemical poisons are sprayed, they are indescrimate and kill good and bad bugs. All of the different insects have specific jobs. Ants- Sanitation, they clean up what someone has dropped in the yard or on the side walk. Or in the kitchen where the food was left out.