Insects provide an excellent model for examining concepts in endocrinology in the classroom. They are relatively inexpensive to rear, short-lived, and free from animal welfare regulations. Using the tobacco hornworm ( Manduca sexta ) as a model, we have developed a simple laboratory experiment to demonstrate the role of hormones in development. In this experiment, students will use a readily available agonist to disrupt insect development, preventing metamorphosis. This exercise fits well into the AP lab curriculum and the NGSS LSB.1 objectives.