Yes this is such a really bad habit I used to bite my nails as a kid and I still do to this day especially when I am anxious or stressed

I would be inclined to look into why he is excessively biting his nails, just due to the fact excessive nail biting is associated with stress/ nervousness /anxiety issues. I am a believer in finding a prevention rather than having to find a cure.
On a lighter note, I tell my children when they chew their nails ,, ‘ they are consuming more germs chewing their nails than you’d consume licking a toilet seat’ fingers retreat from mouths pretty rapidly!!
Good luck with your son!

I used to love that bitter nail paint that mum would put on me… I stopped biting my nails when I was about 12….. it was my choice as mum had given up years before!

Why not try by putting bandaids on his finger tips?

I would check if the biting is due to stress, boredom, nervousness or anxiety. Sometimes play / sand therapy will help because it keeps them (& their hands) busy.

I wouldn’t go with the chilli option purely because I’d be afraid that mine would rub their eyes and end up in a world of hurt!!! I’d go the reward option….

Goodluck, our little one bites her toe nails also and we haven’t been able to stop it

the nail polish tip sounds good

Check when he is biting them? Is it when he is tired, nervous or stressed? Or is he bored?
If you can watch the times he does this, then you might find something to distract him.

Just wait when he falls sick, then you can tell him it is because he is always biting his nails. My 4 year old stopped biting his nails, when he had a severe tummy ache and I just reminded him of the fact that he bits his nails and then on he has stopped biting them.

I was and is a nail biter ( not as bad as before)……….what work for me is nail polish. If I put nail polish then I won’t bite. Not sure if that will work on kids.

Is it anxiety related? Maybe get him in to see the doctor

chilli oil worked on my friends daughter who did that

what i was going to suggest has already been written! good luck

try to give hot chili sauce maybe

The reward option sounds good

Maybe put something that he does not like to eat on his fingers and make sure it gets in under his nails as the taste will stay there. You can also show him how germs live in under the nail, try and find something that he can watch that will sure do the trick.

reward when they don’t bite them. put a star chart on the fridge a star a day for not biting their nails. 5 stars = a small prize. crayons , coloring book etc

My thoughts would be to try rewarding positive behaviour – often – or just leave it and let him grow out of it of his own accord. Good luck!

I was a thumb sucker and nothing my mum tried worked, I just stopped of my own accord when I was ready.