Odd Brittle star

[Zerandise]

I have a star that is being just a bit odd. HE has spent most of his life with me hidden in the rocks. I see an arm here and there. well last night after the lights went out he starts to curl up on the glass. I found it a bit odd but what the hell ya never know. well apon the lights coming on this morning i found him to still be there. Seems he had spent the night digging and most of the morning. he dug a pit around 1 inch deep. As i write this it just moved from its new hole and returned to the rock work.

Any ideas?