What use to science is a pesky organism that feeds on rotting fruit? Professor Bambos Kyriacou has spent fifty years observing the behaviour of fruit flies. He keeps them in the lab and in his garden in their thousands, has recorded fruit fly courtship songs using a microphone loved by Jonny Carson (because it made his voice sound deeper) and invented equipment to keep track of their sleeping patterns. He tells Jim Al-Khalili how fruit flies sparked his interest in genetics and how experiments with insomniac fruit flies opened our eyes to the fundamental importance of body clocks.