There was a ghost
I was sitting outside with my bunny Oreo playing some p!atd and suddenly he starts thumping and I'm thinking "he's probably scared of the train noises," but then the train passes and he's still thumping so I think "maybe he doesn't like p!atd" so I pause it. Then he runs over to the corner staring at something under my chair still thumping with his back arched and I'm thinking "there's probably a mouse under my chair" so I get up and look but there's nothing there. So I tell him to relax and walk inside. I'm sitting in my room and my cat has just woken up from a nap so she's slowly walking around when she stares at my door with her back arched and her tail up like she's about to chase a mouse. And then she looks at the floor next to her and paws at it like there's something she's trying to get. Then she just lays down and falls asleep again. There is only one explanation: there was a mouse ghost.