Padraig was sitting crosslegged on a snatch of rug (or, to be precise, the coarse weavings that rugs came wrapped in). He had a captured mouse, a rock, and a bowl. When he saw an approaching pedestrian who looked like a Brahmin, he would pin the mouse down on the ground and then raise the rock as if he intended to smash it. Of course he never actually did smash the mouse, and neither did Jack, when Jack took his turn. If they smashed the mouse they would not get money from the Brahmin, and they would have to spend valuable time searching for a replacement mouse. But by assiduously threatening to smash the mouse all day long, they could collect a few paisas in ransom money.