Nano and his older brother, Felix, are best friends who read each other's minds and have super-secret phrases, like "totally grape." They do everything together! Like playing dino smash monster truckers ("Hey! That's MY car!") or being a pair of totally amazing artistes--until somebody's squiggly line crosses straight through Felix's perfect picture ("Moooom! Look what Nano has done!"). Nano can't wait to join Felix, the bestest big brother ever, inside his incredible tree house . . . but hang on, what's that sign that says "No Nanos Allowed"? Fine! He'll just build his own tree house . . . or rain house . . . wind or no wind . . . In Ben Mantle's classic story of squabbling siblings--the younger one adoring, the older in need of space--the comedic illustrator brings a fresh touch and signature visual humor, building up to a heartwarming denouement sure to resonate with brothers and sisters everywhere.