How do we know they aren’t screaming the whole time underground where no one can hear them?

Because when they are underground,
they have no mouth and they must not scream

That’s why once they start they only stop when they die 😊

If I lived in the nice dark underground, suckingb down sap from tree roots, and oblivious to the outside world for my entire childhood then I too would be content and scream-free too

Shout! Shout!
Let it all out!
These are the things that you do without