Mother's Day Fun Part 2 - Matt and Ella's Weird Mystery Game

We spent the afternoon/evening outside on Mother's Day - for much of it, Matt and Ella were playing a game. A game unlike any other game. A game I did not understand, nor was I invited to play (although Ama was). Since I have no idea what the game was, what the rules were, or even what was happening - all I really know is that it involved a lot of running, laughing and girlish screams (by Ella, not Matt thankfully) - I can only post these pictures and hope that someone, somewhere might be able to explain it to me one day.