I mean, I never would, but only if I had to. Have you heard of the guy who ate his own crap to survive? I don't know, but if it really, REALLY came down to it, I would reluctantly do so, I think. Like if I was on a deserted island with no food or something. Same goes for anything else mentioned, including humans (call me barbaric or whatever, but in that situation I don't think I'll have much of a choice)