Smarter than the average bear

We're in the office and Alex grabs the phone off the charger and takes off with it laughing.  I chase after him and snag the phone back.

He returns, grabs the phone off the charger again, takes off laughing, closes the office door in my face and runs away.  I open the door and find him hiding behind one of our sofas pushing buttons on the phone.  I snag the phone back.

Undaunted, he returns again and hands me a toy and babbles something to me.  I take the toy and look at it, saying inane things to him like "Wow, isn't this a great toy. Thank you!"  while continuing to surf the web.  I hear the door shut behind me and the sound of laughter.  He's stolen the phone again after distracting me with the toy.  Again I grab the phone and I put it up on the printer out of his reach.

Alex returns once more, again with another toy.  But I'm on to him, and besides, the phone is out of reach.  He busies himself by getting into the box we have under our desk that hold receipts.  He opens it up and flings receipts all over the room.  I move him out of the way and start cleaning up his mess.  Just as I'm about done, the door closes and I hear an evil toddler laugh and the sound of him running away.  The phone?  It's gone.  I still don't know how he did it, but clearly the kid can outsmart me.