Four little domestic episodes about Michael, the smallest and quietest in a large, noisy family. In the first, Michael is briefly left behind after a picnic, and though he's gratified that he's been missed when the family returns for him, he has also appreciated the uncommon silence. In the last, with everyone else scrambling madly for ways to retrieve a dropped key, it's Michael--ignored as usual--who quietly goes about fishing it up from between the porch planks with kitchen magnets attached to a yardstick. ""From now on, everybody listens to Michael,"" says an admiring Kevin, the oldest at 15, and he is echoed by all--including, at unnecessary length, the author. The rewards here are small (there's the satisfaction of fooling Grandma when she comes to ""baby sit"" Michael and sister Connie, though both children object to the term); the main weakness is Thompson's failure to bring the lively family to real life. There is no wit to their cheerful joking, and the wildest scene--involving spilled tomatoes in a minor car accident--is forced and fiat instead of funny.