Explore the fascinating world of Drosophila neuroscience in this comprehensive lecture by Katherine Nagel, part of the ICTP-ICTS Winter School on Quantitative Systems Biology. Delve into the advantages of using Drosophila as a model organism, including its compact genome, fast reproduction time, and sophisticated genetic tools. Discover how the fruit fly's nervous system processes sensory information, focusing on olfaction and motion vision. Learn about the mushroom body's role in odor learning and memory, and understand how directional motion is computed within the fly's brain. Gain insights into cutting-edge research techniques, including connectomics, electrophysiology, and genetic manipulation, that are advancing our understanding of neural circuits and behavior. This lecture provides a solid foundation for students and researchers interested in quantitative approaches to systems neuroscience.