An unlikely friendship holds fast despite challenges in this boy-meets-squirrel tale. From the moment little Squill leaps into Will’s bassinet, the two remain inseparable, despite the best efforts of two sets of parents to separate or distract them. Singing to each other—“Squill will if Will will!” “Will will if Squill will!”—the two enjoy years of wild romps. Until, that is, Will’s parents bring home a kitten. Though a small, spiky figure in the author’s Marc Simont–style watercolors, Squill exhibits very visible irritation at being left out. Eventually, a tail-pulling incident sends the unrepentant rodent off in disgrace. The fence is mended, though, after Will discovers that his kitten is more interested in naps than rowdy play. Squill has fallen in with a girl interested only in pushing a stroller around, and so they engineer a trade. The tongue-twisting text further animates this take on a well-worn theme. (Picture book. 5-7)