Jokes combine with nursery favorites in the paper-over-board Hey Diddle Riddle: A Silly Nursery Rhyme Flap Book by Wendi Silvano, illus. by Tad Hills, with sturdy, laminated pages. A nursery rhyme-based joke appears on the left (""Who waddled his men up to the top of the hill and down again?""), and a flap on the opposite page reveals the answer (""The Grand Old Duck of York,"" naturally.). Hills's full-page illustrations often provide clues to the punch lines.