Addicted to the movie "Cars" Caderyn now sets all of his tractors up like this in reference to this scene.
So I couldn't find the actual scene, but basically Lightning McQueen and his friend Mater sneak into a field to "tractor tip" just like cow tipping. When they scare the tractors they fall on their backs and fart. Caderyn thinks its hilarious. Thus the basis of Caderyn actions with his toy tractors.