Nail biting!! booger eating!! how to stop?

= NAIL BITING =
I have this thing which I always bite my fingernails! Why can't I just stop? Even though I keep on trying.. I still bite them. That's why my nails aren't long and they're ugly.
-- How can I stop biting my nails?
PS : I don't bite my toenails, it's too disgusting.

= BOOGER EATING =
I see that my friend eats her mucus. eeew. It's kind of gross! She's asking me if how could she stop. She described me how it tastes like, it's kind of salty and it tastes good (she said). She's kind of popular but if people will know she eats booger, they're going to embarrass her! How to stop? Do you think she has worms in her belly already?

Nail biting: You can buy this liquid from the chemist that you coat your nails with, and the taste is so awful, it stops you biting them.

nail biting, you have to stop by fighting against your sef. you have to get rid of all the stress^^
boogar eating, you have to think that it is not good 4 you and you can die, hope this helps^^~~

lol she eats her boogers thats just funny lol extreme turn off too
rofl definently not a s3xy move
nail biting I think theres this stuff you put on them to make them sour or sumtin herd
it works
lol salty and tastes good? lol I feel liike puking