For centuries, people have recognized that rats and mice are not only a nuisance but are a public health problem. Rats and mice damage and contaminate food, damage structures, and carry diseases that threaten health and quality of life, and they can cause injury and death. This manual describes techniques to help us protect ourselves from these disease vectors by gathering information (surveillance) about infestations and about the causative conditions of infestation. Accurate record keeping by public health officials provides the information needed to manage rodent and other pest problems.