In chapter 4 what started happening to tree ears bowl each afternoon

Every afternoon, the wild animals would finish the food Tree-ear was saving to share with Crane-man. The animals licked the bowl clean. Thus, Tree-ear was forced to find a hiding place. Several days later, Tree-ear was even more shocked, as the bowl, which was half full.... was now filled to the top. From then on, the bowl was full when he returned, and there was enough food to feed them both.... Tress-ear and Crane-man.