Watch children brainstorm new words to a familiar song, The Wheels on the Bus. I'd not heard this novel song about trains before nor did I hear it again.
I've seen this type of brainstorming interaction (dynamically adding to and modifying another's ideas) in a number of TV shows of creatives, like script writers and musicians. Extraordinary actions for three-year-old children.
These little kids are fascinated with babies. "I have a baby in my tummy. Do you want to pat her?"