Please note that the content of this book primarily consists of articles available from Wikipedia or other free sources online. The term “pesticides” subsumes various substances, products and techniques used to control pests such as plants, insects, animals and birds. Pesticides include a wide variety of chemical agents, ranging from synthetic chemical substances used to destroy unwanted species of plants to natural chemicals repelling insects and larger animals. They are used to kill vectors of diseases and pests that damage crops, however, pesticides may have negative effects on health and the environment. Learn more about pesticides, their use and effects on health in this book.