8 year old boy non-stop nail biting, finger chewing - driving us CRAZEEEEE

[Parka]

My DS is 8. He's always been one for chewing things and generally fiddling (he loved stroking his ear when he was a baby, and was a pretty avid thumb-sucker until he was about 5) - but now he is pretty much chewing his nails or sucking his knuckle all the time. I'm prompted to post this after spending this afternoon watching him playing football - with his hands in his mouth almost the whole time.

Does anyone has any suggestions about how to handle this? I don't think it is about anxiety - yes, he does it when he's anxious (like school assemblies) but then he does it all the rest of the time too. It's really starting to wear us down - I try not to snap at him when I see it, but it just does my head in sometimes and I can't help it. His nails are down to the quick and must really hurt. We have tried the nail biting lotion but it didn't seem to put him off - but I might see if I can find another brand. I wondered some kind of reward/incentive, but my husband isn't that keen. I have talked with my son about, and the idea we came up with which I might try is something he could have with him all the time to fiddle with instead of chewing (but I need to think of what that might be!).

Any ideas very welcome...

It's going to be really hard to brake the habit. It might be worth secretly filming or take pictures of him at different times to show him what he looks like. It might help him become self aware.
Your going to have to start telling him he's doing it all the time. Between you choose a word you say like 'chewing' that you only say. Agree this word means take your hands out your mouth. Saying a sentence sounds naggy. Buy some light cotton gloves and get him to wear them at home for the next few weeks to help brake the habit. Give him worry beads or a squeezy toy to occupy his hands. When out you could put medical tape on his fingers but this will fall off.
Good luck this is not going to be easy.

Watching with interest as I have a 7yo dd who is the same. She doesn't realise she does it because it happens when she is concentrating, eg, watching a film, reading, listening to a teacher...

We have tried a thumbsie, nail biting solution, reasoning, punishing, incentivising... All work a little bit but I have to sustain it singlehanded as DH never remembers and neither does dd. And sometimes I just don't want to be in at her about the whole time, but she has been told she will need to see an orthodontist when she is older as she has made her teeth so crooked

I am a 36 year old nail biter and pen chewer. I also have an avid thumb, clothes and pen sucker of 6. I've tried everything I can think of and she just carries on. Like mother like daughter. It is an anxiety / comfort thing and a very difficult habit to break.