Cat needs constant attention

Question
Hello! About a month ago, my roommate brought her cat from her mothers house to live with the two of us. She, my roommate is rarely home so I am the main entertainment for the cat. He is a very sweet cat, but he constantly needs attention. The moment I walk in the door he doesn't leave my side. If I go to the bathroom, he whines outside the door. Anytime I am sitting down, he must be on my lap. He gets angry if i do not let him. When I try to set him down he hisses or tries to bite me. If I try to ignore him, he will meow non stop until i play with him. What is going on?

Answer
Hi
this sounds like a very insecure cat and he he is displaying symptoms of separation anxiety. He may be really missing his previous home and is transferring his feelings of insecurity onto you.
Unfortunately the only real solution is the cruel to be kind solution. Cruel only in the sense that you have to teach him to be more independent of you, which means not pandering to his every whim and only giving him affection when you start it. This can be very hard and may take some time for the cat to learn. The cat must also be given something else to keep him occupied, this can be in the form of more toys or even another companion animal depending on your circumstances.
i have written an article about separation anxiety in cats (link below) for more information.

Good luck and best wishes

Kate
http://ezinearticles.com/?Separation-Anxiety-And-Your-Cat&id=858571