According to the movie Elf, reindeer need a good dose of Christmas cheer in order to fly.
...a little bit of...
...a reindeer fly.
That is assuming your reindeer are made from typing paper (we printed and cut out a reindeer template, in wallet size format, from a Christmas Coma craft), and you have a good dry day. Electrons build up on the surface of things better when they are insulated by dry air.
Coincidentally, a good dry day is also exactly the sort of day you need for candy making. So, if the reindeer are really flying, it's time to whip up a plate, or two of peanut brittle (or whatever Christmas candy you happen to have on your list).
Make hay while the sun shines, and candy while the air is dry.