I’m not a physicist, but it seems like they’re a little magic, in that they’re so far from our normal experience, since gravity is proportional to the inverse s

I’m not a physicist, but it seems like they’re a little magic, in that they’re so far from our normal experience, since gravity is proportional to the inverse square of the distance, and the distance to their center of mass is relatively very small, so you can get an extremely strong pull relative to a normal object of the same mass. It seems like even a very small black hole falling onto things could snowball, unless there’s something that counters that? Do black holes lose material/get less dense/evaporate under certain conditions?