Bull snakes make interesting captives....They eat warm blooded prey almost exclusively, which makes it easy for the keeper. They can get quite large, and there are well documented reports of bull snakes over 7.5 feet in length. However, there are strains of bullsnakes in the hobby that don't grow quite this large.
They are remarkably variable in temperment...Some are "dog tame" (pardon the over used cliche) and some remain cantankerous and sometimes downright aggressive throughout their lifetimes....Even snakes from the same clutch can be all over the map in terms of temperment...When threatened, they put on an impressive display. They'll blow themselves up with air, face their aggressor, form their neck into an "S" curl and expell air very loudly through their mouths. The sound is remarkably similar (in my opinion) to a car tire going flat....Even for a completely non-venomous animal, a large bull snake having a bad day can be intimidating. However, they all are not like this, and I know of plenty of "gentle" bullsnakes that take well to handling and are thoroughly enjoyable captives.
In terms of caging, this species does not have alot of special requirements. A thermal gradient (low 80's on the warm end and low 70's on the cool end) is helpful so that the snake can choose what temp it likes at any given moment. A water bowl, filled with clean water is essential at all times. a hidespot is also necessary. I find that dishwashing tubs with a hole cut out in the side work well for my Pituophis...Others use corkbark, coconut shell, etc and these can be good hidespots as well. Basically, you're lookng for a hidespot that allows the snake to retreat from the world in seclusion. In my experience, most snakes like to feel somewhat "crammed" into their hidespots, as this gives them security that they are in a closed, secure environment.
I use shredded aspen for bedding on all my Pituophis (I keep northern and black pine snakes) and I find that it works well. These snakes enjoy burrowing into it, and this gives them an added sense of security. Use a thick layer as a substrate, and you'll find your bullsnake will like to disappear within it. Aspen is also moisture absorbent, and scooping out feces is easy....
Well, hopefully I've been helpful!
-With a fistful of steel,
-AzAtrox