Why is it so hard to break a bad habit?

Many people deal with a nail-biting habit at some point in their lives. Some will go to great lengths to try to stop, employing strategies like dipping their hands in salt or wearing gloves. And while not all of us are nail-biters, most of us do have a habit we'd like to kick. So, what's the best way to break one? Explore how habits are formed, and discover tips on how to manage these behaviors. [Directed by Sacha Beeley, narrated by Alexandra Panzer, music by Carlos Magaña Bru, cAMP Studio].