People's hearts are like wild animals. They attach their selves to those that love and train them.
Animal abuse is rampant in the U.S., right under everyone's eyes, for the entertainment of the public. The brutal confinement and pain of training methods of wild animals in the circus, the aquatic and theatrical shows, leads to retaliation by the animals. Eventually they find the right time to strike out, and they will.
Wild animals never kill for sport. Man is the only one to whom the torture and death of his fellow creatures is amusing in itself.
It was wrong to capture wild animals and confine them in captivity for people to go and gawk at them. And that's basically how zoos got started. But once you do that, and once you have animals that have been bred in captivity, you're really stuck with them in some sense. You can't return them to the wild.
Some kinds of animals burrow in the ground; others do not. Some animals are nocturnal, as the owl and the bat; others use the hours of daylight. There are tame animals and wild animals. Man and the mule are always tame; the leopard and the wolf are invariably wild, and others, as the elephant, are easily tamed.