Although zebrafish are distant cousins of ours on the phylogenetic tree, they share key features in brain organization, function, and pathology with human. This includes a propensity for epileptic seizures when exposed to chemoconvulsants or in the context of certain gene mutations.2 This can be demonstrated even in very early larval stages, mere days after fertilization. Furthermore, the larvae’s small size coupled with advances in microscopy now allow studies that are impossible in any other vertebrates. As shown elegantly by Diaz Verdugo and colleagues, with calcium imaging in larval zebrafish, we can now track changes in brain-wide activity at single-cell resolution during the transition into epileptic seizures.