How do early birds get up in time to catch the worms? A clock in our brains helps us maintain daily, or circadian, rhythms. Dr. Joseph S. Takahashi discusses the natural history of biological rhythms and explains how he and other scientists have unraveled the complex workings of the body’s clocks. Biological clocks are key to understanding jet lag, various sleep disorders, and why teenagers have a hard time rising early. From the Series:HHMI’s Understanding Biomedical Research Series