Inspired by the classic rhyme: ``What are little girls made of?" and ``What are little boys made of?" David Greenberg has supplied his own take on the matter, celebrating the differences between boys and girls. The left side of each spread describes girls for boys, and then the right side answers with the girls" takes on boys. Greenberg"s text is both gross and hilarious. Joy Allen"s expressive illustrations are full of clever details. This humorous, reassuring blend of insights and insults is perfect for raucous read-alouds between boys and girls.