heh its called war people, the only natural predator for man is man, hence why racism and national separation still exist in our so called enlightened, civilized world. we are the same creature we where when we where killing each other with rocks and sticks in the stone age, we just use guns and bombs now, and wear jeans. nothing hunts us anymore though, we killed off most of the worlds apex predators, the only place you will see a gray wolf or a tiger is a zoo, instead of worrying about overpopulation we should worry about how we will fight world war 3 without nukes. personally i think world peace, overpopulation, and the irresponsible draining of natural resources can be solved in one fell swoop, all the worlds governments fight every other world governments in a giant battle royal. winner take all, the rules are simple. no wmds, no guerrilla tactics, only open war and the result will be a reduced population, one government, and enough resources for said population.