Black holes as laboratories: searching for ultralight fields

The interaction of black holes with classical fields can lead to many interesting phenomena such as black-hole superradiance and the superradiant instability. The existence of these effects has been shown to have implications for beyond Standard Model particles that could explain dark matter, namely ultralight bosonic fields. In this note I give a historical account of this topic and briefly go through some recent developments. I conclude with some personal reflections on the importance of constraining simple dark matter models, even if such models may ultimately be the incorrect description of nature.