I can now most assuredly confirm that Zebes does NOT like moss in his hide, at all. Checked on him this afternoon and he was in his other hide on the cool side (which he just about never uses) and it was very obvious the poor guy was stressed. Halfway out the hide, clearly awake and in a frightened, glaring S-pose. I promptly moved all the moss out from under his other hide and my back was barely turned after re-securing the lid that I saw he had scurried back across the enclosure and curled up completely inside it like he normally does.

Guess I found one of his first quirks.