On the topic of the sand (probably the least of the enclosures problems) as a horse owner and vet tech I've seen sand colic kill a horse. I know different animal but if it impacts something so much larger probably not great for something so small. Yes, a little can pass no problem but quantities will weigh down and irritate the bowel. In the wild and in a bioactive they might get a few grains no biggie but hunting on a bare sand floor is going to be worse. Do we know for a fact that they feed on the floor or do they put them on the plants? I'm hoping that that enclosure is just having some plant problems and wasn't supposed to look like that.