A scientist has developed a secret weapon for the army whose rays are supposed to shrink enemies to miniature size. Unfortunately, a test ray strikes Donald and his nephews. The Ducks are astonished when they suddenly are as small as ants. Gyro Gearloose seems to be the right man to give them back their normal size. So the mites start out on an adventurous journey full of deadly dangers. On their horror trip they are nearly run over by bikes and cars. After Donald and his nephews have spent the night in a can they luckily reach the ingenious inventor and finally get their normal size back.