“Boynton’s books work best when they address adults and children together. In But Not the Hippopotamus, the title character does not partake in other animals’ activities: “A hog and a frog cavort in a bog. But not the hippopotamus.” At the end, the group invites her to join and she agrees: “But YES the hippopotamus!” Joy and comfort seem assured. Yet, just then, on the final page: “But not the armadillo.” Like all good literature, it leaves interpretation to the reader…For years, readers begged for a follow-up that would resolve the matter. Last year, she finally gave in and published But Not the Armadillo. After pages of gratifying, mostly solitary activities—napping, strolling, picking cranberries—the book invokes the earlier story’s ending: “A happy hippo dashes by. She wants to run and play. But not the armadillo. No. He goes the other way.” Don’t sit out if you want to join in—that’s the hippo’s lesson. But equally valuable is the armadillo’s: You don’t have to take part if you don’t want to.”
—Ian Bogost, “Sandra Boynton’s Captivating Universe.” The Atlantic. November 2019.