Commensal rodents pose health risks and cause substantial damage to property and food supplies. Rats have also invaded islands and pose a serious threat to native wildlife, particularly raptors and seabirds. Estimates of total damage from introduced rats range into the billions of dollars in developed countries. This book aims to provide a state-of-the-art overview of the scientific advancements in the assessment of exposure, effects and risks that currently used rodenticides may pose to non-target organisms in the environment, along with practical guidance for characterization of hazards. This will be discussed in relation to their efficacy, and the societal needs for rodent control, and discussion of