There are a lot of different reasons people bite their lips. It's happened to everyone at least once, when they least expect it (ruining a perfectly good bite of food!). For some people, though, it seems to happen all the time, accidentally, while they're talking or eating. Others do it in their sleep. And for some lip biters, it's a habit, induced by stress or because their lips are dry and flaky. The first step to solving your lip biting problem is finding out which of these categories you fall into, and then find a plan of action for saving your lips!