Tillie and the Wall By Leo Lionni

All her life Tillie the mouse has wondered what lies on the other side of the wall. Imagining all sorts of fantastic possibilities, she digs a tunnel to get to the other side, where she discovers . . . other mice, just like her! Together, Tillie and her friends work to bring down the wall and unite mouse-kind. Written just before the fall of the Berlin wall, this seemingly simple fable has a powerful message for all children—and all people.