As the sleepy keeper bids him good night, Gorilla snitches his keys; then he creeps after him, letting the other animals out. In a lengthening parade that includes a mouse first seen taking one of Gorilla's bananas, they pad along behind the keeper like faithful dogs, enter his house, and curl up to snooze in his bedroom; Gorilla snuggles into bed next to the keeper's wife. The man is too drowsy to notice, but she does; taking Gorilla by the hand, she leads the whole parade back to the zoo with an air of resignation that suggests this has happened before. Gorilla certainly knows the ropes; he and the mouse (still toting the banana) follow her back, this time to settle in the middle of the bed. The amiable cartoon characters, vibrant palette, and affectionate tone of the author's art recall Thacher Hurd's cheerful illustrations. Delightful. (Picture book. 3-7)