Over the last few decades, scientists have been busy debunking the myth that nonhuman animals relate to each other in a primarily competitive, aggressive way. What they have found is that many species of animal, including many of those most closely related to humans, display a remarkable range of cooperative, "prosocial" behavior. In fact, it appears that some animal societies adhere to a moral code. What is preventing us, then, from saying that the members of these societies are moral beings? Nothing important, according to a recent book. Probing further into this question, I suggest that in fact quite a lot is at risk in making this move. To integrate nonhuman animals fully into the moral domain, we may have to adapt our conception of morality in some very troublesome ways.