Leaf-Cutter Ants Can't Digest Leaves

So why are they carrying leaf cuttings into their hives all the time?

Leaf-cutter ants are also known as farmer ants, because they farm a fungus. The ants collect leaves from the forest, bring them down into their hive and hand them off to colleagues. Those ants mulch the leafy bits up with some ant spit, then feed the results to the fungus, which metabolizes it. In return, the fungus creates edible projections called Gongylidia and oozes nectar, all of which feeds the ant colony.

Happy fungus, happy hive. It's one of nature's beautiful symbiotic relationships.

By analogy...

Similarly, many humans try to make sense of the world by taking notes, enhancing those notes, and exploring shared notetaking. tktk

More on the ants

Here's an informative introduction to the symbiotic relationship some ants have with fungi:

Finally, here's another documentary on the subject, Planet Ant: Life Inside the Colony, plus this nexus in Jerry's Brain.

This all to explain our fondness for the metaphor of The Big Fungus.