Death is what makes us human not the intellect. agree?

What makes us human is our desire. Because we desire, we keep coming back to do it all again. There's no intellect in that, in fact it's a form of ignorance. We do have a chance to 'go beyond' but only with the wisdom that allows us to free our mind from thinking that all phenomena has inherent existence. Animals can't do that but they can be 'punished' for killing in the sense that they take another lower rebirth because of their karma.