Earlier quoted context omitted.
How on earth do you know that? And what difference does 'knowing' make? Do they make the sacrifice or not? They clearly do.
By reading, being educated. Its far to late to be mystified about how animals work. Its a couple of centuries of study by now, about their instincts and behaviors. And recall, 'understanding the concept of sacrifice' was the topic.
It can be slow and inefficient to make up for lack of equivalent materials and mechanisms. A simulated one will do.
Or just explain how it works. I've been looking forward to reading that book. You'd sell some copies.
Also, a nitpick: it's a few millennia of studies by now. For example you can read Aristotle on the topic from 1700+ years ago.