Squirrels don't even remember where they've buried the acorns. They just bury and dig, and with enough squirrels involved it works out. Its an instinct that happens to contribute to survival.
They sacrifice something - an abundant summer acorn - today to get something better - a scarce winter acorn - in the future. It's a clear counter example to the claim above.
Except they don't mean to do anything. They're carrying an acorn, they pass a juicy spot, they feel compelled to stick the acorn in the spot. At no time does the squirrel think "I'll sacrifice this food now for food later!" So it's not reasonable to call it a sacrifice except metaphorically?
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.
