ok, I've had reptiles before( toads, geckos, skinks) but never snakes. but about a week ago, I was sort of dumped a black rat snake( I know, not really a corn but theres no blackratsnakes.com...) he's about 3.5 feet long, but I know they can get to 5 or 6. I put him in and old 29 gallon tank I...