I don't see them having cities and driving around in cars etc. I get your point re canibalism
It was sort of tongue and cheek but I will meander slightly in the second paragraph lol
Animals will eat or kill those things that are weaker than them should they wish to. I also don't see why it is wrong to kill I mean there are all sorts of societal exceptions like self defence or euthanasia - this is the real meat and potatoes when you get to the crux of making a non eating meat decision for real.
Also re vegetarians - cows have to go through the anguish of being separated from their calves and then the pain of being hooked up to milking machines, I don't see how this is an ethically enlightened way to treat an animal at all, what do you think?