We were at my in-laws' ranch at that time. Before that video was recorded, we're all playing with Abi's ball, kicking, throwing, and catching it until all of a sudden Abi was all alone with himself, playing with the ball.
The thing where he's rolling the ball is actually a small grilling pit. The top is just enough to hold the ball and have it roll there. No one taught or showed Abi to do it and he just came out with that idea. It's just so amazing how simple thing can entertain them. We just wish that those things would cross our mind so that we always have something for their entertainment.