Where does the stinkbug in my room go?

I got a stink bug in my room that I’ve been letting chill bc he doesn’t really do nothing.

My question is this -

Usually, he’ll be gone during night. I don’t see him. Come day, I hear him fly into the window n just chill walking around the window and shades, and then repeat.

What is he doing during night? Is he sleeping somewhere? How is he surviving in my bedroom of all places?

Figured here might be a good place to ask. Thanks 😁👍