"Warning: To avoid danger of suffocation, keep plastic bag away from babies and children. Do not use this bag in cribs, beds, carriages or playpens. The plastic bag could block nose and mouth and prevent breathing" -- a common and standard warning found on plastic bags and similar plastic sheets.
I remember enjoying popping small bubble wrap between my fingers when I was younger. And I still do to this day. It's oddly soothing for me.
Despite the warning, I laid a sheet of bubble wrap on our floor. It was an open invitation for the kids to pop the air-filled plastic bubbles.
The bubble wrap made it extra fun and motivating for Matthew to practice jumping -- not that he really needs any extra motivation to jump these days ever since acquiring lift-off with both feet simultaneously. He'll jump just for fun even without bubble wrap but it was more fun to hear pop! pop! pop! with every jump. Of course!
What big brother does, little sister tries too. Matthew can jump about 2 inches off the ground and land feet first on the bubble wrap. Pop! Pop! Pop! Elizabeth positions herself -- arms to her side, feet wide apart, knees bent -- then tries to straighten up to jump but lands bottom-first on the bubble wrap. Pop! Pop! Pop! Then she laughs and does it again and again. And again.
We're adding "jumping on bubble wrap" to our list of fun gross motor activities (done with adult supervision).