Little humans know all about kisses with lips, but how do you suppose an anteater would kiss? Or a tree frog? Or a humpback whale? Readers up to 6 will meet a dozen different animals and their young here, each with different sorts of mouths, then imagine what their goodnight kisses might be like. Heather Swain provides additional nature notes, and Steven Henry gives all of these critters adorable faces—even the piranhas.