Christmas themed fact! 
People assume that the song refers to "Calling birds" when, in fact, they're actually a kind of bird known as "Colling birds".
EDIT: Nevermind. It appears I am incorrect. Hmm, I could have sworn...
EDIT 2: Okay then, back up Christmas fact. During Saturnalia, it was customary to eat biscuits in the shape of humans.
People assume that the song refers to "Calling birds" when, in fact, they're actually a kind of bird known as "Colling birds".
EDIT: Nevermind. It appears I am incorrect. Hmm, I could have sworn...
EDIT 2: Okay then, back up Christmas fact. During Saturnalia, it was customary to eat biscuits in the shape of humans.