Sleep is one of the most mysterious, yet ubiquitous components of our biology. It has been described in all major groups of animals, including worms, jellyfish, insects or cephalopods, and in all vertebrates, from fish to humans. Common characteristics of sleep include reduced movement, decreased muscle tone, and an increased need for sleep after periods of deprivation, for example after a night out. Recent research at the Max Planck Institute for Brain Research provides important insights into how sleep rhythms are controlled in a reptile, the Australian dragon (Pogona vitticeps).