Invasive species are threatening the environment and the economy. These newcomers and their impact on the ecological balance are the focus of this material, a guide to learning skills for investigating the behaviors of non-native and native species. The reader will discover the links among biology, ecology, and environmental studies -- as well as the important connection between science and public policy. Studying invaders such as zebra mussels, chestnut blight, purple loosestrife, and Phragmites, the reader will explore how scientists are fighting these aggressors with biological controls. This student edition has three sections: 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 worksheets to serve as a guide through the student's own interactive research.