We dug our cobalt out yesterday. We have had alot of problems getting her to burrow at all, because she didnt like any of the substrates we have tried. I finally put her on bone dry peat and she dug right in. The problem with that is that I ran out of peat and she only had about two inches depth. So yesterday we added a bunch of peat, and we dug her out because she had a big piece of cork down there with her, and we didn't want her to freak because there was suddenly all this deep peat on top of her burrow.
She took it pretty well I suppose. Although she was kinda pissed. I don't actually suggest doing this on a regular basis or anything though.