Owing to the power of free association, and for no other apparent reason, this thread brings to mind another Grandpa/Grandma ditty:

    "Caviar comes from the virgin sturgeon,
      The virgin sturgeon's a very rare fish.
      The virgin sturgeon needs no urgin',
      That's why caviar is my dish!

      I fed caviar to my Grandpa,
      He's a man of ninety-three.
      The virgin sturgeon needs no urgin',
      He chased Grandma up a tree!"