High school chemistry can be intimidating to some students, so it is critical that we engage students in nonthreatening preparatory investigations during middle school. Based on the learning cycle model (Bybee and Landes 1990), this lesson invites students to investigate disposable diapers. As they explore the properties of sodium polyarcylate, a super-absorbent polymer exposed to water and simulated urine (colored salt water), students practice many inquiry skills: observation, measurement, graphing, and data analysis. (Contains 4 figures.)