The other day Bella was using the litter box and when she finished she covered the poop but then scooted her butt on my floor and left tread marks on my floor. She has never done this before. As I was cleaning the mess up, she sat there and looked at me like she was so sorry she did it. I had to laugh but tried not too and I think she knew she did something wrong. My question is this; why do cats do this and has anyone ever had this problem too ?