This wonderful Mouse Box Set, by Beverly Cleary, contains four books: The Mouse and the Motorcycle, Ralph S Mouse, Runaway Ralph, and Strider.The Mouse and the Motorcycle

Ralph only wanted to ride the mouse-sized motorcycle someone had left on the table in the hotel room where Ralph lived. Instead, both Ralph and the motorcycle take a terrible fall into the wastepaper basket, where they are trapped until Keith, the owner of the motorcycle, rescues them. Keith teaches Ralph to ride the motorcycle, and the two of them soon find out that adventures can be both fun and dangerous!Ralph S. Mouse

When Ralph's home at the Mountain View Inn is over-run by rowdy mice who want to use his red motorcycle, he packs up his prized machine and moves to a new home -- inside Irwin J. Sneed Elementary School! Runaway Ralph

Ralph has made up his mind -- he is going to run away. Envisioning fun, freedom, and delicious crumbs from peanut-butter-and-jelly sandwiches, he hops on his red bike and zooms away to the summer camp down the road. Once he arrives, he runs headlong into a strict watchdog, a mouse-hungry cat, and even more fur-raising escapades. Suddenly home doesn't seem like a bad place to be. Strider

In the sequel to the Newbery winner Dear Mr. Henshaw, Leigh Botts is down in the dumps. His parents have divorced and his dog has run away, and it doesn't look as if things could get any worse. But Leigh's life takes a turn for the better when he adopts a stray dog named Strider.