"Cats are all about stalking. We have fond memories of growing up with indoor/outdoor cats who would bring us the severed heads of chipmunks and moles. (It's only slightly less creepy than waking up with a dead horse on the pillow next to you.) We're really not sure what happened to the rest of the bodies, but the heads were delivered in a neat little line outside the front door. Were they a gift... or a warning? The Zig-N-Zag Ball plays into your kitty's hunting instincts. The ball-within-a-ball mechanism is self-winding and will send the ball zigging and zagging erratically when hit. Gone are the days when a ball would obey the laws of physics! (Okay, this one still does, but in a more roundabout manner! Down, physics geeks! Down, boys! and girls!) What matters is that your kitty will assume this ball will act like all their other balls, but as soon as they swat it, those assumptions will fly out the window. Fight kitty boredom and provide hours of exercise with the Zig-N-Zag Ball! Product Specifications Crazy cat toy that rolls around unpredictably when swatted Self-winding mechanism, no batteries required Smart toy for smart cats who are bored with normal balls Satisfies kitty's need to stalk prey Dimensions: 2"" diameter Assorted colors: Please allow our robots to choose one for you"