So I added the moss into the hide to fix the humidity problem. I added it along the outer edge of the hide so that the snake can be in the middle of the hide surrounded by the moss. Apparently, that's not the way he likes it! :p

KMG mentioned he just put a clump of moss in there while I tried to arrange it along the circumference of the cave hide.
I guess KMG was right in how he did it, cause my snake arranged the moss in the middle himself! lol

I wish I could've seen him gather up the moss from the sides and put it in the middle, but unfortunately it would be hard to do without a transparent hide (which defeats the purpose hehe) or x-ray vision. The only thing I can see is the end result: