If you've got a playful cat that can't get enough chase, consider picking up – and putting down – a collection of Jitter Critters ($8) for your feline's frisky fun. All you do is pull the string of the mouse, squirrel, tiger or hedgehog versions and let your kitty do the rest . . . plus, there are no risky batteries involved for those chew-prone pets. Purrrfect!