Ok I have a question to ask all you mommies out there. My 18 month old will play with his toys and then giggle like he playing with someone else. His older sister passed away when she was 14 months old and his older brothers were at school or asleep. He would put a toy down and run away from it then turn around like he was waiting for it to come back to him. Could it be that he is playing with his sister? Please no negative comments.