omg yes Sophie does that sometimes! I swear she sees things. Lately she hasn't done it, except today for like 2 seconds but i think it's cause she saw a shadow from the car lights outside, sometimes they show up on my wall as cars go by. One time though when i first got her she was barking all day at spots in my room. Next to my bed she would bark at the floor and shake and be scared to go there, it made me think it was my dead dog Charlie. I was like aww you met Charlie, don't worry, he's friendly