@TalesFromTheArmchair @vicgrinberg
Black holes form when something provides enough energy to overcome the pressure that stops things collapsing in on themselves. One of the things that can provide enough energy is gravity, if you have enough of it, and that gravity comes from getting an enormous amount of matter together in one place.
Another way of overcoming that pressure is by smacking things together _really_ hard. If you could smack two peas together hard enough that the matter that made those peas ended up inside their own event horizon, you'd have made a tiny black hole.
There are some very high-energy things whizzing about the universe. If they hit the right things in the right way, they could form tiny black holes.
Regarding the not popping back out again: once that stuff is inside its own event horizon, there's no popping out: nothing crosses the boundary the other way.