How do you stop a fourteen year old from sucking their thumb?

I had a friend with the same problem (although actually a lot older) She bought a big thumb ring so that she would notice when she was doing it -as it got in the way. You could also try that nail varnish which tastes disgusting which is usually used to stop nail biting.

Thing is you have to talk to them and they will have to want to stop themselves. At fourteen you can't really just force them. Don't make fun of them about it it will only make it worse. Try, "I notive you still suck your thumb a lot - do you want my help stopping it?" They will probably already want to stop but be at a bit of a loss as to how. Maybe you have done this already.

Good luck