Hiding in Plain Sight

We were driving home from Grammie's last year when the girls started talking about their Christmas list. Interestingly, their requests sounded just like the presents we had hidden. Daddy said they knew what they were getting. We agreed to play along to see how long they would last before telling us.
After Christmas they confessed that they had found our hiding spot. I told them they were both very good actresses as they seemed surprised on Christmas morning.
This year we're not hiding anything. All their Christmas presents are being delivered to the front door. One box sat in the family room for days. They never paid attention to it. They are so conditioned to think that we're hiding their presents that they don't even pay attention to boxes as they bring them into the house.
We've decided to annoy them a bit this Christmas. Today Daddy wrapped a box for each girl and put it under the tree. We didn't put names on the boxes. If you shake a box, you can tell that there is more than one thing inside. We'll continue to randomly put packages under the tree until Christmas morning. If nothing else, it entertains us. The girls will pretend they don't care, but we know they will be trying to figure out what is in the boxes when we're not around.