science

I don't mean it that literally. I mean just observing swaths of people putting straws into drinks, putting ointments on scrapes, etc might make them extrapolate and try similar actions using what's available to them.

It's not much of a reach for a primate seeing a human manipulate and dig with a shovel, and use that as inspiration to manipulate a bamboo shoot to scratch their own back.

We homosapiens spent 180,000 ish years wandering around in the dirt like idiots before it occurred to some of us that we could grow food in one place, thus beginning the path to civilization. Even we need examples to extrapolate from.