Alan Roberts is a distinguished electrophysiologist, neuroanatomist and student of animal behaviour. His sustained investigation of the circuitry that underlies behaviour in amphibian tadpoles has transformed our understanding of a spinal network generating rhythmic movement and its regulation by sensory and descending inputs. Inspired by Coghill to work with simple networks in an embryonic vertebrate, his detailed cell by cell analysis provides unique insights into the developmental origins of connectivity and its functional significance.