A motto observed in a researcher's lab—``When all else fails, read the directions''—sums up this tale of a mouse who's sent a ``construction kit'' by her friend Rat and assembles a wheeled vehicle (she calls it a ``Biker-Riker'') that does run- -but with an excess of unwanted ``wheelies.'' Reorganizing the parts, Badger comes up with ``Jaloppy-Doppy,'' different but no better—as is Otter's ``Boater-Roater.'' Shrew, however, finds the instructions, lays the parts out neatly, and puts together an airplane that flies them smoothly to Rat's for a birthday party. The lively, well-drawn animals (all female) and intricate contraptions are fun, though more might have been done with using identical components in the different configurations (cf. Tryon's Albert's Alphabet). Still, entertaining. Seven-piece construction kit of the airplane (with instructions) included on jacket flap extensions. (Picture book. 4-8)