I think I'll settle with aspen as the substrate of my choice. I haven't been able to find the perfect choice but aspen works pretty darn well. Aspen holds a burrow well and absorbes quite a bit. While ingestion is a problem, I've had snakes eat a good bit and pass it without incident. Definately something to try to prevent though. I feed in the enclosure but just keep an eye and make sure they aren't getting mouthfuls of aspen. I'll give it a 9/10.