Dax's hiding place

So each night after Dax goes to sleep, I put all of his books and toys back on the shelf. This usually takes about, I don't know, 10 minutes or so.
Anyhow, I put like-toys together again. So all the blocks into his block container, his shape sorter pieces into their bucket, etc.
If pieces are missing after everything is put away, I search. I find little toys and shapes on the window sill, on dining room chairs, under the couch, etc.

I haven't been able to find 2 of the 3 balls for his tree toy in more than a week! They just disappeared. Plus one of his blue (favorite) shapes from the shape sorter toy had also gone missing.

Yesterday, I saw Dax reaching his chubby little arm on top of the our DishDVR box, which is in a slot under the TV stand. He was fussing about something. I went to look. He was trying to stuff a triangle shape behind the DishDVR box. But it wouldn't go back there so he was frustrated and kept trying to push it down.

Do you know why it wouldn't fit? Because there were 2 balls and a blue shape back there already! Wow, I never would have thought pull out the DishDVR box and look behind to see if some little baby was hiding toys back there! I removed the toys. Dax saw them and his whole face lit up. He then crawled around the house while holding a ball in each hand so that his crawling makes funny noises (he does that a lot - he's crawl while grasping a block and go on the tile floor to make clip clop noises) to celebrate.

Also, Dax has started enjoying a baby version of "hide & seek" I leave the room he's in and go somewhere else and "hide" behind a door or a chair. Then I call out to him, "Where's Mommy?" And he giggles and laughs and crawls to my voice. If I'm hiding too well, I have to call out to him again, which makes him resume giggling and then he finds me and squeals in delight. It's so adorable!