Scientists have captured flu viruses in real time as they move along the surface of human cells. They used a breakthrough imaging technique that made it possible to follow this process with high resolution. They discovered that human cells are not just passive victims, but actively reach out and "catch" the virus. This movement allows the virus to find an ideal entry point into the cell. The study showed that flu viruses move along the cell membrane much like surfing. These findings help to better understand the mechanism of influenza infection. The results may contribute to the development of new treatment approaches.