One day I was sitting on the couch while Gabe played on the floor and he was very quiet, I looked down at him and he had covered himself with his play mat and was very still. I said "Gabe..." and he giggled and kicked his feet really fast and paused again. i said "Gabe..." again and he did it again so I walked over and slowly pulled the mat off. He laughed and laughed and has been playing peek-a-boo ever since!