My mom calls Little Brother "The Whistler." He's very proud of having learned to whistle. I know he's happy when I hear him whistling away (tunelessly, but happily.)
He was walking around here like a sleepy little zombie a few minutes ago, so I sent him to wash his hands and face and brush his teeth. I could hear the water running, and then he started to whistle.
It takes a special kind of talent to whistle while you brush your teeth.