How To Train Your Drone is a novel human-drone interaction that demonstrates the generative potential of a design metaphor: the umwelt. We describe the concept of the umwelt and detail how we applied it to inform our soma design process, creating an interactive space where somatic understandings between human and drone could emerge. The system was deployed for a month into a shared household. We describe how three people explored and shaped the umwelts of their drones, leading to unique and intimate human-drone couplings. We discuss the compatibility of the umwelt to soma design practice and identify future avenues for research inspired by artificial life and evolutionary robotics. As our contribution, we illustrate how the umwelt as a design metaphor, can open up a generative new design space for human-drone interaction.