"Sana, Sana, Colita de Rana" goes the song. The silly little chant means, "heal, heal, little frog tail." The second line follows, "si no sana hoy, sanará mañana" which means, "if it doesn't heal today, it'll heal tomorrow." When a mother sings this to an injured child while rubbing or tapping their boo-boo, they laugh instead of cry.
Photo via Flickr CreativeCommons, Michael Bentley