Do as I'm Doing...

Katie and Scotty were on the bed with Daddy as I was singing to Kara to put her to bed. Katie got this wild hair and all of the sudden began to roll like a steamroller while singing the primary song, Do As I'm Doing. Scotty for some unknown reason was on the same page, and began doing the exact same thing. They rolled over and over each other, singing that silly song. Do you know what they were immitating? Katie said they were being the arms that roll over and over when you sing that song. Random. Funny. Where do they get it?