"Good night, Gorilla," says the weary watchman as he walks by the gorilla cage on his nightly rounds at the zoo. The gorilla answers by quietly pickpocketing the guard"s keys, stealthily trailing him, and unlocking the cages of every animal the oblivious fellow bids goodnight to. Looking much like an exhausted father, the uniformed guard traipses home toward his cottage, while the lonely zoo animals softly parade behind him. The animals manage to slip into his bedroom and nestle unnoticed near his sleepy wife--until the bold little gorilla goes so far as to snuggle up beside her as she turns out the light. Author and illustrator Peggy Rathmann (creator of the Caldecott-winning Officer Buckle and Gloria) relies more on the nuances of her jewel-toned pictures than on words to pace this giggly bedtime story, making it perfect for observant preschoolers. In one inky-black spread, Rathmann lets only the shocked, wide-open eyes of the guard"s wife tell us that the gorilla has been detected! Tiny details such as the faithful, banana-toting mouse and sky-bound pink balloon that appear in each picture keep this book fresh, magical, and fun--even after countless bedtime readings. (Baby to preschool) --Gail Hudson