2. Keep Them Busy
You may also want to get into the habit of keeping your hands busy. There are lots of ways that you can do this. Many people choose to set up their laptops while they are watching television and you can rest are hands on the keyboard and mouse and look up stuff while you are watching TV. This gives your hands a place to rest and helps to combat the urge to bite your nails.
In addition, you can use tools like yo-yos or fidget spinners to keep your hands busy. But that is not the only way to combat biting your nails. If you remove your hands from the equation, then it is unlikely you are going to bite your nails, but if you remove your mouth through the equation as well, then the chances are almost nil. You can do this by chewing gum or sucking on a mint or Jolly Rancher.