The fish stick is an easy-to-use device for conditioning fish under classroom conditions. It is constructed from inexpensive plastic pipe available at most hardware stores and uses electronic components available at retail electronics outlets. Fish press a nipple for baby food which can be brought under stimulus control using lights, vibratory cues, or both. The fish stick is suitable for inquiry-based experiences in courses on the psychology of learning or comparative psychology. Data are presented using a continuous reinforcement schedule and discrimination learning. Students report that the fish are easy to train and enjoy the hands-on experience.