New technologies have enabled students to become active participants in computational simulations of dynamic and complex systems (called Participatory Simulations), providing a "first-person"perspective on complex systems. However, most existing Participatory Simulations have targeted older children, teens, and adults assuming that such concepts are too challenging for younger age groups. This paper, by contrast, presents a design for a Participatory Simulation, called BeeSim, which makes use of wearable computers and targets young children (7-8 years old) to model the behaviors of honeybee nectar collection. In our preliminary user studies, we found that BeeSim contributed to systems understanding and more easily managed group dynamics. (Contains 3 figures.)