nibble nibble

I've just realised I have some pretty weird habits. I know it's common for people to bite their lip, but I bite on a little more than just my lip.

When I'm bored, I chew on my hangnails.
When I'm thinking about something, or being pensive, I bite the inside of my right cheek.
And when I'm bothered by something, I'll chew on my lip.
...
That's kind of freaky. Does that mean I like eating skin??