Back Lightning is a type of twitching that happens through their back that is, at least partially, a spasm, but also a way of getting that energy out. You may notice your cat walking across the room, then suddenly stopping as if a fly just landed on him, and then very deliberately grooming himself. This self-soother is also a self-regulator. It’s also a reliable indicator to you that your cat’s energy tank is just about topped off.

