Forget about using bitter nail polishes and other products of this ointment - they are ineffective and useless, because you will be able to get used to this taste. Biting your nails is a bad habit, but it doesn't happen without a reason. Therefore, it is worth considering where this habit comes from and when it appeared.
Typically, this problem concerns people who struggle with stress, anxiety or neurosis. If the problem is caused by the above-mentioned reasons, it is worth considering what you can do to eliminate or reduce your stress level. For example, contact with nature reduces the level of cortisol, the stress hormone. This means that even taking a twenty or half-hour walk in nature like in the forest will lower your stress level, relax and unwind you. You can also engage in void meditation, breathing exercises and yoga there.
Try to keep your hands busy. Always have something (It can be anything like for example pencil) at your fingertips to keep your hands occupied and shift your focus on this activity. There are also toys, such as an anti-stress ball, to which you can shift your attention. Use nail clippers and shorten your nails as short as possible. This will let you help to learn a new habit in which you will use nail clippers systematically.
Moreover, bitten nails not only result in an unsightly appearance, but can also lead to health complications. It's worth reading about it as a warning.