Switching genes between organisms and controlling an animal's brain using lasers may seem like science fiction, but with advancements in a technique called optogenetics, such experiments are now common in neuroscience research. Optogenetics combines recombinant DNA technology with a controlled light source to help researchers address biomedical questions in the life sciences. The technique has gained the most traction in neurobiology--the biology of the nervous system--where specific wavelengths of light are used to control or measure the activity of neurons in transgenic organisms (i.e., those with artificially inserted genes). In this article, the authors describe an inexpensive "Drosophila" (fruit fly) optogenetics experiment used to teach principles of the nervous system, genetics, and bioengineering at the high school level. Optogenetics combines recombinant DNA technology with a controlled light source to help researchers address biomedical questions in the life sciences. Fruit flies are commonly used in high school laboratories to teach principles of genetics. This activity scaffolds on those basic principles by applying fruit fly genetics to concepts in neurobiology and physiology. The authors found that students have fun controlling fruit fly behavior with LEDs and gaining practical experience with a genetically modified organism. The lab also covers several "NGSS" standards.