Do your adult bloods somehow just find their way under the flat newspaper substrate to make their own hide
Oh, they find a way under the newspaper. The key is to clean their enclosure thoroughly, put down paper, making sure that they CANT get underneath it.

Then about 15-20 minutes later, you will find your blood snug and gleeful UNDER the newspaper. LOL

I have found that the bloods are cheerful and laugh at you when they are under the newspaper, but for ball pythons, they tend to be anti-social, and there is rumor they dont like the sun (like vampires).

Those two species both get pure enjoyment out of peeing and urating within hours of a new change of substrate.