No. But don't suck on your thumb, it's weird.
They CAN suck their thumb, however by that age, they should have grown out of it.
No.
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
Suck it..... ; )
no one knows that
yes
Yes and, in fact, there are a plethora of adult thumb suckers who currently exist.
they should not be and u need to get that stopped
Get him to suck something else...
you will get an over bite KOrenblatt