Hands-on activities with live organisms allow students to actively explore scientific investigation. Here, I present activities that combine guided inquiry with direct instruction and relate how nutrition affects the physiology and behavior of the common housefly. These experiments encourage student involvement in the formulation of experimental design, promoting engagement in the learning process. These activities are suitable for both postsecondary education and high school classroom settings and highlight National Science Education Standards, particularly by promoting inquiry-based learning and communicating science explanations.