Ball pythons will also get alot of the water that they need from the meals that they eat. Ensuring that your food items are well hydrated, if you feed live, I guess it would be hard to make a frozen mouse drink water, will help to keep your ball python hydrated. I rarely see any of my ball pythons drink. As far as roaming at night, like everyone else has said, they will usually come out for a little while, but will not typically roam all night. Remember that in the wild these snakes spend the majority of their lives in old rodent burrows. Your snake sounds like it's doing fine to me.