Once upon a time, Etwas the Elf was running through the forests of tall grass, under the canopies of clover around the stems of the tall flowers when she came upon an acorn lying in the grass next to the stream from a leaking pipe. She ran around until she found just the right rock and pried the cap off of the acorn, placed it in the stream and made a boat of it. She pushed away from the bank and soon was spinning her way downstream.
After a little while she saw the palisades of a paw print from a dog and so she grabbed a pine needle and poled her way over to the damp paw print. She moored her boat (using the same pine needle) in the claw mark and tried to climb out of the deep toeprint but the wall was slippery and Etwas got herself covered in dark soil before she could reach the top.
When she arrived, she saw a trail of ants carrying pieces of someone's picnic and she snuck up on one and grabbed the tiny bit of salami from its mandibles.
The ant looked at her and, seeing her mud-crusted face, thought she was an ant too.
"What a splendid idea!" the ant shouted. "Guys, let's stand upright!"
All the ants behind, and the ones before all stood up one after the other and toted their meal with the haughty strides of an animal that has learned to walk erect. All the way to the anthill, they discussed the arts while Etwas the Elf ate her lump of salami in the bottom of the dogtrack.
And ever since then, whenever Etwas the Elf meets a line of ants, they all do the wave in a series of courtly bows.