Part of a Christmas Eve tradition, reindeer food is sprinkled on the lawn to attract Santa's reindeer (and Santa!).  Clear tubes are filled with reindeer food (oatmeal and edible glitter mixed together) with instructions on the attached label.  "Sprinkle on the lawn at night, The moom will make it sparkle bright.  As Santa's reindeer fly and roam, This will guide them to your home."