I chew my fingers
When I get bored I chew the skin on the tips of my fingers. Sometimes I do it pretty bad, to the point where the red layer underneath the skin is showing or sometimes it even bleeds a bit. I don't bite off huge chunks of skin or anything like that, it doesn't hurt that bad while I do it...normally. It hurts afterward sometimes, especially when I handle certain chemicals or acidic stuff. I used to chew my fingernails, but I guess I sort of replaced that habit with this.
Is this normal?