In this bustling picture book, Mr. Postmouse carefully loads up his wagon and sets off to make the day's mail deliveries to all the animals on his route. Via cross-section drawings, readers get to peer inside each home Mr. Postmouse stops at, and every one is different, depending on the animals who live there. For example, there's a hole in the middle of the kitchen floor of the Rabbits' home that leads underground to where they sleep and eat. Mr. Snake's superlong home has heat lamps throughout its length. The Birds live in a tree house, and Mrs. Octopus in a sunken shipwreck. Mr. Bear's house has a beehive on the roof with an attached pipe that brings honey straight into the kitchen. Furnishings in Mrs. Fly's home are stuck to the ceiling.