It's hard to overstate just how weird black holes are; we don't understand much about them, and the little bit we do understand suggests that they don't behave like anything else in the observable universe. They function like rips in the fabric of space-time itself, pulling everything—even light—out of view, where we can't see it. We can speculate that there's an infinitely-dense singularity at the heart of a black hole, but for all the evidence we have we could speculate it's just about anything else with an equal degree of falsifiability. Some scientists speculate that each black hole creates a fresh universe; others speculate that black holes that gobble up matter are nonlocally connected to white holes that spit it out. We just don't know.
We might be able to figure out more about black holes if we had some sense of how they were created. The Science Channel explains the prevailing theory regarding how small black holes are formed, with a little help from Bad Astronomy's Phil Plait (and some of the most impressive special effects you've ever seen):
But persuasive narratives and eye-catching CGI are no match for empirical observation; as far as we know, we haven't actually seen a black hole form. Fortunately, NASA's Wide-field Infrared Survey Explorer (WISE) may soon put an end to that by showing us objects that are becoming black holes, giving us a better sense of how these bizarre anti-objects come into being (or anti-being, as it were).