This book contains the student edition of the Environmental Inquiry curriculum series developed at Cornell University. It is designed to teach learning skills for investigating the behaviors of non-native and native species and demonstrate how to apply scientific knowledge to solve real-life problems. This book focuses on strange intruders invading parts of the world, threatening the environment and the economy, and their impact on ecological balance. The natural links between biology, ecology, and environmental studies and the important connection between science and public policy are illuminated. Three sections present background on the science of ecology and its place in the control of invasive species; protocols for practicing methods that scientists use in monitoring invasive species such as early detection surveys, plot sampling, transect surveys, and decomposition studies; and a series of helpful worksheets to guide interactive research. (KHR)