<p>Stellar evolution makes us believe that we have over 10 million stellar-mass black holes (BH) in our own Galaxy, whose total mass should far exceed the mass of the central black hole. For half a century we have known that stellar-mass BHs exist, from the few dozen X-ray binaries, where tidally torn material from a very close stellar companions accretes onto the black hole and makes it shine? But is there actually this vast population of dormant BHs, either in wide binaries with a normal star or just free floating? The hunt for these BHs is now on, using ESA’s Gaia mission and other facilities: we have now detected the first dormant BHs in binary systems, after some spectacular earlier misidentification of BH impostors. And, there is first direct evidence for free-floating BHs by means of microlensing. These first discoveries already pose interesting puzzles about how these BH systems could have formed. The next few years offer spectacular prospects of finding far more dormant BHs, whether they are free-floating or in binaries, which should teach us how and when stellar-mass black holes form.</p>
