If you have a compulsive behavior, this may be the answer to stop, or at least bring some awareness to it.

Couple in crisis
Ridofranz Getty Images

I have had the nail biting issue since I was a kid.  Sometimes it's worse than other times, and it does seem to depend on the level of stress.  Just picking or biting or whatever.  Some people have a hair pulling issue, or any number of other things.

There is now a bracelet that reacts when the behavior happens.  It vibrates just in order to bring the subconscious behavior into the conscious.