On a moonless night in South Africa, a dung beetle that has shaped its ball climbs on top of it, turns a slow little dance to take a bearing, and then rolls away in a straight line, steering by the Milky Way. Researchers showed this in 2013 with a planetarium and some tiny cardboard caps: hide the sky and the beetles wander in loops. What I like is that the beetle has no destination. Any direction will do. All it needs is not to curve back towards the dung pile, where the other beetles are waiting to steal the ball. It is using the whole galaxy for the humblest job in navigation: not going round in a circle.