Hello. I have a 4 years old cat. She often behaves very nervously, meows, wants me to be near her all the time. I give her plenty of attention but she seems to want more. When I'm at work, she usually just sleeps. When she's anxious she'll often find a quiet corner and start biting her own tail tip. There's already no hair there. Sometimes she'll do the same with an area on her paw but the hair grows again there when she stops biting it constantly. I cannot understand what causes this behavior. She was spayed when she was 1 year old. Thanks in advance for your help!