Who signals santa the children are asleep in I love Lucy the Christmas episode?

In the "I Love Lucy" Christmas episode titled "The Christmas Show," it is Little Ricky who signals Santa that the children are asleep. He does this by placing a note in the fireplace that says, "Dear Santa, we are all asleep," allowing Santa to come and deliver presents. This moment adds to the festive charm of the episode and highlights the innocence of childhood belief in Santa.