No. But don't suck on your thumb, it's weird.
they should not be and u need to get that stopped
They CAN suck their thumb, however by that age, they should have grown out of it.
No.
Babies mostly do
Sucking of the thumb is a bad habit that cant be stopped easily. Wrap paper tape on your thumb if it there you wontwon't want to suck it. Do this for some months. The habit should stop.
you suck your thumb
Yes you will your fingers or thumb pushes the teeth to the front and the top of your mouth goes up and u will most likely have messed up teeth at the end. if u do get braces do not suck on your fingers or thumb it will ruin your teeth permanently
yes
Yes and, in fact, there are a plethora of adult thumb suckers who currently exist.
you will get an over bite KOrenblatt
Get him to suck something else...
With the advent of the Internet the subject of adult thumb sucking has left the shadows and, as a result, it is now well known that adults do, indeed, suck their thumb. The best estimate, so far, is that affects about 2% of the adult population in the United States.