Show the kids how to cut hearts out of a folded sheet of red, white and pink paper, or cut them ahead of time to save time. Glue hearts of various sizes on construction paper to make Valentine animals. For example, a 4" heart right-side up, with another 4" heart below it upside down makes a torso and lower body (overlap the two points a bit). Add two small hearts at the bottom and two more on the sides for paws, two 1" hearts on the top for ears, and small hearts for eyes and nose, a row of tiny hearts for a tail (or a piece of yarn), add some whiskers and it's a mouse. Very inexpensive, and the kids can get very creative.