Explore the fascinating world of fly navigation in this lecture from the ICTP-ICTS Winter School on Quantitative Systems Biology. Delve into the intricate mechanisms behind how flies determine their heading and direction of travel, with a focus on the ellipsoid body and its role in spatial orientation. Examine key experiments, allocentric heading angles, and the complete fly brain EM connectome. Investigate the functions of EPG neurons, Delta 7 neurons, and the ER4m circuit in supporting navigational processes. Gain insights into cutting-edge research on fly neuroscience, including work by Sharon Su and Rudy Behnia on alloception, in this comprehensive exploration of sensorimotor control in insects.