Question: Burrowing A. lugubris?

[Lugubris]

I have an A. lugubris that I have had for nearly a month, and ever since I started using coir (or ground coconut husk) as a substrate, he seems to be obsessed with burrowing. The reason why I am concerned is that I have another slightly younger A. lugubris that couldn't care less about burrowing and instead spends his time climbing all over the place, as I thought A. lugubris were apt to do. My burrowing specimen does not move very much, and even before I used coir as a substrate, he would stay hidden under a piece of a flower pot I provided for him, only bothering to move if he was disturbed or eating (he wouldn't come out of his cave when feeding, he would wait until the food was right in front of him). The substrate is kept damp and it includes a drainage layer of sand, and the temperature stays between 50 and 65 degrees. He was also still eating as of last night.

When I found him he was stuck in a buried irrigation control manifold, covered in scars, emaciated, and with a broken leg (the leg is now healed and he is at a healthy weight). I am guessing he got into the irrigation control manifold to estivate when he was younger and was unable to get out of after growing larger, and the scars (which have also healed) and broken leg were probably from a territorial dispute or a predator. A few nearby irrigation manifolds were swarming with wood lice, which would explain how he could grow too large to get back out.

Is his burrowing a sign that his cage is too dry (I doubt it, its pretty damp) or that he could be sick? Or is he just used to living underground and feels more comfortable that way? Or could he be trying to hibernate (although I have seen evidence that this species will not unless the temperature drops below freezing)? Is his overall lethargic behavior something I should be worried about or is this all just normal behavior? Any advice is appreciated.

 

[Lugubris]

I believe I found the answer to part of my question in the third and last two replies of this post, it seems that I did not soak my coconut husk fiber long enough (it seems soaking it for 24 hours is better than 25 minutes like the instructions mislead you to do). It was slightly too dry for my A. lugubris so he burrowed himself down to the more damp drainage layer of sand. I thoroughly soaked it now and he is back to his usual routine of hiding in his cave.

Some species specific information about the lethargy and lack of climbing would still be appreciated, but at this point I'm not too concerned because he is at least back to his usual self.