People often think pesticide means insecticide .
Actually, pesticide refers to not only insecticides but many other kinds of chemicals. A pesticide is any substance intended to control, destroy, repel, or attract a pest. Any living organism that causes damage or economic loss or transmits or produces disease may be the target pest. Throughout history, pests have caused problems. Dinosaurs may be extinct but a prehistoric creature of another sort, the cockroach, has been crawling the earth for 350 million years.