When their mothers take obstreperous Sam and Laura to a library, a restaurant, and a department store, the children are so uproarious that they have to leave each one. Solution: after a mild lecture (``airplanes don't belong in stores. And monsters don't belong in restaurants''), they all go to a playground, where the kids scream and shout and ``their mothers thought they were wonderful.'' Caseley's cheerful, expressive illustrations convey as much about these hellions and their parents as the spare text. The events are almost painfully realistic, with the mothers' laid-back responses verging on satirical. The book doesn't waste much sympathy on the victims, but it may give some kids—and parents—a fresh point of view on their own behavior. (Picture book. 3-7)