i live in my basement, and at night, my cat walks around down here, and he will look over to the stairs, or in our family room, which is creepy to just look at, (for me anyways) and just hiss, and run under my bed. and he has no claws, but he still acts like hes scratching them on stuff, and he jumps onto our bottom stair and our second from bottom stair, and starts scratching then he looks up the stairs like he sees and hears someone coming, even when i hear and see nothing, and his ears get flat on his head, and he hisses and runs.