>>1986698>>1987444This is one of those cases where you can't generalise all animals.
Some species instictively kill all prey animals they come across. This applies to wolves who happen to get into animal pens for example; they'll kill FAR more than they'll ever eat. Some animals, however(mostly primates), know how to show restraint.
I think humans can be put in the later category, since while not all of us show restrain, we at least have the ability to do it.
Also, I can't stress enough how important it is not to generalise here. You simply can't address the insane amounts of different organisms that inhabit earth under the same label, such as "animals" or "nature". Like humans, other organisms, too, are complex, in physiology as well as behaviour.