When I was young, my mother would recite a nursery rhyme to us that featured two little birds. She used to smoke Paul Mall cigarettes, which had a blue 20 class stamp on the pack. She would tear off the stamp, moisten it, and place it on her finger, alternating fingers to create the illusion that the blue stamp was vanishing. , she would recite the rhyme:
"Two little dicky birds sitting on a wall, one named Peter, one named Paul. Fly away Peter, fly away Paul. Come back Peter, come back Paul."