It is often challenging, especially at the beginning of a course, to find good examples where students can actively explore and grapple with the methods of science. We want them to learn the connection between observation, theory, prediction, evidence, and falsification, but to really accomplish this we need platforms for which the students are able to design and implement experiments, and we need to be able to see the results of those experiments relatively quickly. There are some nice ideas using games and simple demonstrations and labs. I have found an example that is both entertaining for the students and rich enough in behavior to be an ideal platform for introducing scientific thinking: the automatic flushing toilet (Fig. 1).