Mice explore such well-known objects as a telephone, eyeglasses, and a book.

Unlike the other mice, who are incurious about the wall that has always been part of their world, Tillie is determined to find out what lies on the other side of the wall.

From sunup to sundown, winter through fall, Leo Lionni's signature illustration style and a toddler-friendly text ask a simple question: When is time of day/season? One of four board books that celebrates the art and imagination of Leo Lionni, this book is a perfect introduction to the concepts of time and seasons for busy toddlers, as well as a wonderful stepping stone into the world of one of our best-loved children's book creators.