I'm a horrible nail biter too. I eat the nails, then the skin around them, then a Bic pen. I think it's an overall oral fixation I have. I have to consciously NOT eat my good/uneaten pens so I have at least one normal pen to pull out in meetings and at court - cause a nibbled pen just looks gross. And, I more than nibble - I'll actually get little bites off a pen.
