Hi ! I have a six month old shih Tzu. We got a crate 2 weeks back . For few days I made him comfortable with the crate and for 2 days he was fine sleeping in the crate nearby my bed. But since last few days and soon as I close the door of the crate he starts crying and jumping in the crate as if trying to open it. I don't want to hurt himself if I leave him alone . What should I do?