Cage size. this is a snake that could certainly benefit from a big cage. They love to get out and crawl around. Perhaps place a few branches in the elncosure, they do like to climb a bit.
Temps. I keep mine at around 85F.
Humidty. I know for sure that my humidity is rather variable, I would say no lower than 40% ever and no hihger than 70%.
Temper. None, my CB snakes seem to have no will to bite, unless you smell like a pinky, DO NOT make that mistake.
Venom. Unkown, supposedly fairly moderate, could ruin your week.
Be sure to put in a large sized water bowl. Live plants (or just some green plant cover like fake ivy or something).
Really neat snakes, very quick. If you had one determined to bite I don't think you could do much to stop it. They could make short work of a hook. You'd just be giving it a ladder to your hand but like I said not inclined to bite.
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It's helped me to keep in mind that these are a grassland snake and not a tree boa or exotic rat snake, don't overdo the humidity.
They will it mice with a fervor that you rarely see in snakes.
Intelligent beasts aswell.