The simple act of feeding bread crumbs to a duck can breathe life into important ideas in behavioral ecology and other natural sciences. That's what UC Davis graduate student Paul Switzer discovered when he designed short campus field trips to give students hands-on experience with field biology. The idea of a "gain curve," for example, seems abstract when described as a patch of food providing a decreasing reward over time. But watching a few slices of bread crumbs disappear as the ducks gobble them up is so clear. Campus field trips are not a new idea, but they may be an overlooked teaching tool, Switzer says in an upcoming paper in the Journal of College Science Teaching. As a teaching assistant, Switzer introduced short field trips into his discussion groups for an ecology class and into his laboratory sessions for an introductory biology class. Often interpreted as time-consuming excursions to more exotic locations, field trips have become endangered teaching tools because of tight budgets, liability concerns, disability access and time constraints. Yet, field trips can add a whole new dimension to a course's content and effectiveness, Switzer says. Short, focused campus field trips can provide many of the same benefits -- at the cost of a loaf of bread.