In the first activity, students “role play” as an assigned organism (or other resource) that must search for a resource (another student) that it would consume. After students pair up in trophic-relationships, they draw their connections within a group-designed food web diagram. The second activity involves an ecosystem-level problem of describing complex biogeochemical cycles. After completing a pre-reading, students work in groups to create a diagram in which they arrange cut-out squares and arrows (that they must label) to illustrate relationships among C or N pools and fluxes. The third activity involves an applied problem of endangered species management and highlights the complexity of human-environment relationships. The problem’s scenario is taken from a real-life court case in which a man killed a cat that was killing endangered birds. In groups, students act as jurors and must debate the issues involved in the case before attempting to reach a consensus about whether to acquit or convict the man (i.e., the problem). Class discussions following each activity can explore many ecological principles but should focus on helping students recognize and appreciate the inherent complexity of ecological science. In this presentation, I will present students’ comments about these activities to support my conclusion that hands-on, learner-centered activities create ecologically dynamic classrooms that foster critical thinking about ecology and thus facilitate students’ development of deeper understanding and appreciation for this complex and important discipline.