ABSTRACT: All too often, designers assume that complex science and cycles of inquiry are beyond the capabilities of young children (5-8 years old). However, with carefully designed mediators, we argue that such concepts are well within their grasp. In this paper we describe two design iterations of the BeeSign simulation software that was designed to help young children learn about honeybees collect nectar from a complex systems perspective. We summarize findings from two studies that suggest that this design has been successful in teaching and motivating these young children and demonstrates how activity theory can guide design.