EcoBeaker is currently the leading software for teaching ecological concepts through simulated experiments. Students use conceptually realistic tools to manipulate communities of simulated critters and discover important ecological ideas. In older versions of EcoBeaker, students and teachers could construct their own model communities as well, but the rules governing behavior of the critters were severely restricted. We are working on a new version of EcoBeaker with a graphical model construction interface borrowed from the StarLogo project at MIT. This new interface allows users to make individual-based ecological models by dragging "blocks" of code that only fit together in reasonable ways. We hope to use this new interface to write laboratories where students build their own models as a way of learning ecology. Here we'll show the new interface and discuss our initial assessment of its effectiveness.