The sea would not move. Rāma's army had to cross to Laṅkā, and there was no bridge — so the vānaras pulled the mountains apart and threw them into the water, boulder after boulder, for days.
Nobody noticed the squirrel.
She was too small to lift a pebble. So she ran down to the shore, rolled in the wet sand until her fur was heavy with it, ran back up onto the bridge, and shook it out into the gaps between the stones.
Then she ran down and did it again. All day, while the thunder went on over her head.
A monkey laughed, picked her up the way you would move a leaf, and set her aside. Not now, little one. This is work for big hands.
And Rāma turned around.
He knelt down. He let her climb into his palm. And he said, loudly enough for the monkeys to hear: the bridge is not only rocks. Her sand fills what the rocks leave open. Without her it is a pile. With her it is a road.
Then he ran three fingers gently down her back.
The army crossed it four days later. It held.
That is why every squirrel still carries three pale stripes. They are the marks of his fingers, and she never washed them off.