Why does your elf on the shelf only move in the daytime when you are not home?

The purpose of the Elf on the Shelf is to watch how the children behave leading up to Christmas. If he is in a spot where he can see a lot of activity, he may stay put. Our Elf moves around but often returns to the same spot more than once. He has been coming for several years and ALWAYS shows up the day after Thanksgiving. We have noticed that he finds hiding spots where he goes unnoticed so that he can really observe the children's behavior without them being aware of him. I have also heard that if you touch him he won't move - try writing a little note to tell him you won't touch him again and see if that works. Good luck!