This morning as I was leaving for work my kitty Leo had such a sad look on his face. Maybe I was imagining it. What can I do to help him? I pet him and say goodbye before I leave. As soon as I get home he is either waiting at the door or at the top of the steps for me. Should I get another kitty? I have only had him for a few months, do you think that he will get used to being home alone?