Chronic onychophagia is the clinical name for nail biting, a pretty common “bad habit”. A girl sat next to me in a class in high school that was a compulsive nail biter, right down to her fingers, which looked horribly infected as the mouth can transfer bacteria and viral infection. There are even medications prescribed for this problem. I suggest dipping those fingers in extremely hot chili pepper oil.
I don’t bite my nails, but I have kind of dry hands so sometimes my cuticles or the skin under it will crack and split and I will bite off the little corners of skin. Horrible I know. Being vegetarian I’m sure to always spit them out. I’m working on it, really it just requires a bit of regularly applying lotion, I just, dislike lotion, I like my hands dry and non-greasy, it’s good for drawing. I don’t usually use nail clippers though either, I use the “soda can tab method”. I just use my other fingernails to tear them off when they get too long, I’m pretty precision at it, but we could probably all do well to spend some time with our good friend, the fingernail clippers.