This is our first cat and we bought him/her from a friend. This kitty is 3.5 months old and has been in our home for over two weeks now. It eats the food I provide and uses the litter box, but either has powers of invisibility or waits until everyone is gone before venturing out. Is this normal? I can't even find him/her. He/she does not have a name yet because we have not been able to get to know him/her. Do I have a cat with abnormal behavior problems? How long is too long for this behavior to continue?