While the entire army of Lord Rama was full of enthusiasm for the fight with the army of Ravana and when the fire of revenge burned in their hearts, the fire also flashed in the heart of a squirrel as well. Most of the members in the army of Lord Rama were monkeys. All of them, standing at the shore of the sea, got instruction to make a bridge so that the sea could be crossed.
Each one of them, started picking up big rocks and setting them up in alignment with each other in order to construct the bridge.
Be it Hanuman, Sugreev, or others in the team, irrespective of their age or health, the zeal and dedication to save Mata Sita showed in all of them. The ocean was deep and wide, but the fire inside the hearts was deeper and wider too. It was all because they loved Lord Rama and Mata Sita and wanted to save her, in any possible way.
It was not just the monkeys and other people in the army, who were helping Lord Rama, but others from the nearby forests and villages had also come to support them. All knew that Lord Rama was the prince of Ayodhya who had come for serving the exile period. Sita Maiya, as they called her, was also one of the most respected and dignified ladies whose being captivated by king Ravana had invited the fury of many. All these, hoping to save her, were now working together to save the Goddess.
Amidst the noise of the efforts and the chaos of all those present, there was one whose effort was being unnoticed. It was a squirrel who had been carrying small pebbles and fitting them wherever possible and thus helping in the making of the bridge. Though the size of the animal was too small as compared to the level of task and the ability of others in the army; her efforts could be called negligible. However, this was not sufficient to move her and it reflected in her confidence, with which she was working.
However, one of the monkeys noticed this little creature putting in her efforts, while he was carrying a very heavy stone. Amused by the squirrel, he told her to get off from his way. He told her not to work since her contribution would be negligible and it wouldn't matter much even if she did not work. Hence, he advised her to go back and take rest. When the squirrel defended, one of the onlookers told about it to others as well, just to make fun of her.
Offended by this, the squirrel went to Lord Rama. She complained about those in the army and requested Lord Rama to punish them in return. Lord Rama asked all the people to assemble at one place near the bridge. As they all came in, Lord Rama, while pointing towards two stones which would have slipped and collided down, had they not been held intact because of a small pebble. He told them that the pebble was brought and put there by the squirrel.
All were surprised to see how a small pebble had been helping to keep both the large stones together. They realised that no act was small or big. An effort made with honest intentions and an urge to contribute to a righteous and virtuous deed is always good. All those who played pranks on and made fun of the squirrel were embarrassed and apologised to her.
It is said that Lord Rama then patted the back of the squirrel in appreciation. This left the mark of three fingers on her back. It is one of the mythological reasons often stated behind squirrels having three stripes on their back.