Quentin Cooper is joined by neuroscientists Kevin Moffat and Richard Baines to discuss how the tiny Drosophila melanogaster, or fruit fly, is providing scientists with intriguing clues about how the brain works and what happens when it goes wrong. Scientists have successfully engineered flies that closely model the symptoms of human diseases such as epilepsy and Alzheimers. They hope that this research will provide a tool that can help to unravel the underlying causes of brain diseases and accelerate the development of new drug treatments.