Human and non-human behaviours are regulated by cycles of light and dark, while many such behaviours can be detected through sound. This article asks how we might use recordings of light and sound to make the nocturnal urban environment meaningfully legible as a more-than-human biome. It reports on several prototypal methods that bring together art/design practices and fieldwork techniques. The aim of this ongoing work is to raise awareness of the night as an ecology, communicate the multiple temporalities characteristic of a healthy biome and provide tools that can inform responsible urban design interventions that improve the quality of the night from a more-than-human perspective.