Ollie is a butt-in-ski. As baby Zach is growing and developing, Ollie has made it his duty to be a part of it. When I have a free moment during the day, I'll usually bring out Zach's play mat to lay on and get some tummy time. Ollie likes to come over and sit right on top of the play mat. He sniffs around at all the dangle toys and gets right in my face to be sure and include him in the activity. Since Zach's toys have lots of bells and whistles(literally), this of course has Ollie ready for play time. Doc and I have been really careful about not confusing Ollie's toys with Zach's toys. We'll have to keep a sharp eye out just in case Ollie gets confused.