You’ve probably seen a weasel ball in a shop window or doorway, confined within a hula hoop and cavorting with battery-powered puppies and pigs. This whimsical novelty toy is a self-rolling ball with a weasel doll attached at the nose. As the ball rolls this way and that the weasel doll flops about in a crazy style.
But with just a little something more, a weasel ball could become jolly fun for a toddler or pet.
Imagine that the ball’s motion became more frantic in reaction to the approach of the wearers of electronic tags, say pinned to a toddler’s shirt and hung from the collar of the family dog. As they got nearer, trying to corner the weasel ball, its motion would get more frantic as if trying to escape (a randomized anti-homing device). As they backed off, it would calm down.