i recently visited the tyler zoo in texas. a very well kept and designed zoo although i was supprized its fee was more than the houston zoo.in the reptile room one room sized enclosure had rattlesnakes,bullsnake,ratsnake,gila monster together in a natural looking habitat. next to that room had a 30 gal. aquarium with a stunted looking texas indigo.(any way to treat a great american snake?) my question is-- is it humane to keep them in an enclosure that small and do other zoos practice that with indigos? steve