Black holes are a product of density, and not necessarily mass alone. As a result, “scientists think the smallest black holes are as small as just one atom” https://www.nasa.gov/audience/forstudents/k-4/stories/nasa-knows/what-is-a-black-hole-k4.html. What is the mass required to achieve an atom sized black hole? How do multiple atoms even fit in the space of a single atom? If the universe was peppered with “supermicro” black holes, then would we be able to detect them?