People and other animals

Just a thought, though there already have been others, who've noted it.
Animal rightists (and by extension vegetarians - this is mostly the case when you stumble upon it) claim we should behave to non-human animals like to the other people. Their life is as valuable as our is.
The problem is, while we can become vegetarians, our natural state is to be omnivore. Yet try to convince some carnivore or herbivore animals not to eat meat (voluntarily).
So maybe after all there is distinction between people and other animals. I don't say animals are less valuable as well as I don't say it about e.g. babies. Yet I behave differently to babies and mature people anyway.