Cats will stealthily approach their prey, and then attack in a flash when they are close enough. At this moment, the cat will first arch its back, and then stretch out like a spring, leaping onto its prey. 
Even if a cat falls from a height, it can roll and land gently without getting hurt because it can arch its back to absorb the impact.
Body languageCats communicate using their backs. When happy, a cat will straighten its back, and when angry, it will arch its back. For example, two cats will not confront each other head-on, but will face each other sideways, staring at each other and judging each other's mood by whether the other's back is arched.
