I think the best option as far as a snake not seeing through the glass is use one of those one way glass materials. Would work great, just be very expensive, Just haveing a enclosed enclosure, with the front just open in a not very bright room i think is not that bad for them.

For rats, would be interesting, but expensive to do, and would never catch on. I would be shocked if the general population could get GMO feeder rats. But nevertheless it would be nice.
Ben