Ever watched a hawk catch a smaller bird? A cat hunting a mouse? More natural than most things humans do, if you ask me.
As for violence in human societies, there's much less of it now than there used to be. But the web provides lots of evidence that "civilization" requires an enforcement mechanism. Without one, it only takes a few people to create chaos.
Much less violence now? Mmmm. That could be worth checking out. But there again you can't have it both ways.
A few with modern weapons? Much more violence and chaos. But hey, we agree with use of violence don't we.