Building on other studies and reports, we describe an educational laboratory exercise in which students analyze the movement of the ciliated protozoan Tetrahymena thermophila, using free video-capture and image-analysis software (ImageJ), along with a relatively inexpensive ($45–70) digital microscope camera that is USB 2.0 compatible. Specifically, students record Tetrahymena activity under different control and test conditions, and they later use ImageJ to analyze the movement patterns. While this technique is demonstrated to show how methanol affects Tetrahymena behavior, students can use the approach to examine activity under a variety of circumstances, enabling them to conduct their own inquiry-based experiments in lab or as part of a larger independent research project.