Hide and Seek!

What do the following have in common?? Ill give you a hint....they are all great hiding places for keys, money, ect.
The past month or so Kooper really likes to hide things, and these are just a few of his famous places...pretty good huh?? NO, not when your the Mom looking frantically for the keys because your late to something, or when your ready to go on a cruise and you look in your wallet and there is $300.00 missing in cash(how did he get my wallet I have no idea)! So when the money came up missing I was actually on the plane with Kooper on our way to Vegas and we were meeting Weston there the next day. I got in my wallet to buy us a drink, (not the type of drink your thinking) they charge for sodas these days! Anyway when I got in my wallet I had no cash, I was dying! So when we landed in Vegas I called Wes to see if maybe he needed it worse than I did and he had no idea what I was talking about but he did mention that he saw Kooper playing with my wallet the other morning. I was thinking "oh great, that money could be anywhere!" So I thought well Ill ask him, never in a million years would I expect him to remember or even know what I was talking about...but I asked anyway and this was his reply..."niener niener niener, I hid your money haaa haaa" Is he serious right now, so trying not to laugh I said very sternly, "Kooper that is not nice you need to tell mommy where the money is, so he said," In the washer mommy, niener niener niener" (where did he get niener niener niener from)?? Sure enough I told Wes to look in the washer, or around the washer and there it was!!
What about the vent your asking....well let me just tell you, he prys the vents off and hides things in there!! What am I going to do with this kid?? The bad news is, he got a leapster for Christmas and we haven't been able to find it since January. I really think he hid it somewhere because we had never even taken it out of the house but we have looked everywhere for it and cant find it....so if you have any ideas we would be grateful:)