I've read a lot about mediterranean tortoise enclosures, but a lot of the information that I've found seems contradictory. There are two main points I'm confused about, any help would be great. One is what should the substrate be made of? The care sheet for them says gravel/sand, but many here seem to recommend various types of wood bits. The other is humidity. The care sheet says they are best in arid environments, but people here seem to say that high humidity is important? Any clarification would be very helpful.