An officious trainee policebee learns to kick back when her "flea-kini"–clad partner drags her to a pool party."Oh, quit being such a buzzy-body!" gripes Bee's extroverted companion, Flea, as an invitation arrives in the splashy wake of a rainstorm. Indeed, once Bee gets over her terror of the water and dives into the puddle to find herself getting a pond-scum pie in the face from Copepod the Clown, being whirled off for a round of "pin the tail on the protist," rescuing a baby water bear, and encountering a host of fellow partiers from heliozoans to daphnia, she considers the whole experience the bee's knees. She even gets a commendation from her partner ("you figured out the water cycle all on your own") after solving the mystery of what is causing the puddle to shrink. Despite expressive faces (and in the case of the cute baby tardigrade, huge googly eyes), the fauna in Deas' frequent illustrations are drawn with enough naturalistic detail to be recognizable, and Humphrey tacks on a set of multiple-choice questions at the end to reinforce the STEM-centric elements she incorporates into much of this chapter book's microscopic mischief. As in Bee and Flea's initial meetup in Bee & Flea and the Compost Caper (2022), there's plenty of entertaining back and forth in the friendship between the two main characters, too.Delivers on the protagonist's promise of "exciting, educational, and occasionally gross" experiences. (Informational fiction. 7-10)