The World According To Humphrey by Betty G. Birney

You can learn a lot about life by observing another species. That's what Humphrey was told when he was first brought to Room 26. And boy, is it true! In addition to his classroom escapades, each weekend this amazing hamster gets to sleep over with a different student, like Lower-Your-Voice-A.J. and Speak-Up-Sayeh. Soon Humphrey learns to read, write and even shoot rubber bands (only in self-defense, of course). Humphrey has friends, adventures and a cage with a lock-that-doesn't-lock. His life would be perfect, if only the teacher, Mrs. Brisbane, wasn't out to get him! Ages 8-12, 144 pages.