I heard about this from someone I know . . . how does Santa really know who is naughty and who is nice? An elf tells Santa, and the elf leaves little things or signs that the children can see that the elf is real. So you have to be good All year round.
It’s evidently a big craze with the younger children started by a mom with her children. I actually remember the style of elf that used to be on my parents and my grandparent’s tree when I was younger, and I remembered it not being my favourite ornament. Partially because they never sat easily -haha
So if you don’t know about it, here is the website: http://www.elfontheshelf.com/