Reclusive tiger salamander

Hello all,
About a year ago I was fortunate enough to get a few of John Clare's CBB barred tiger salamanders. They adapted splendidly while in quarantine, constantly begging for food whenever I was around and absolutely hammering earthworms nearly to the point of obesity.
Back in April or May I moved one of my animals into a 10-gallon tank with about 5 inches of coir/topsoil mix with the plan of moving the other animals to similar setups if this one liked the conditions. Unsurprisingly he made himself right at home and dug a burrow underneath a piece of slate and ended up right at a side pane of glass where I could keep an eye on him. Unfortunately he never again emerged. Since I could keep an eye on him and see that he didn't appear sickly or scrawny, I wasn't too concerned. But this past week I decided he really needed a meal, or at least a checkup, so I dug him up and put him in a dish with an earthworm. He attacked it ravenously but didn't subdue it as quickly as his siblings do, but I suspect his muscles are just a little atrophied. After he finished his meal he buried himself again.

Considering that this animal seems intent on never appearing on the surface again, do you think this is an appropriate setup? I'd like him to be able to burrow and behave at least somewhat naturally, but I don't want him to starve himself to death or have to force feed him twice a year. Thanks all for any input.

-Eric

It sounds like he is comfortable in his surroundings. I would suggest moving all of them to a larger tank with the same set up as the reclusive one. The presence of others may stimulate him so he doesn’t stay burrowed as long. Some of mine occasionally burrow for one to two months at a time even during the warmer months.

Thank you for the reply, Richard. I'm a bit hesitant to keep them all together, since I like to hand-feed most of my amphibians. It allows me to keep a good eye on them and know how much they're eating. I may try a shallower layer of soil for the other two, however... maybe it'll make them less inclined to burrow permanently. It's great that this one is comfortable with the medium and enjoys burrowing in it, but I feel he's so comfortable that he may never voluntarily search/beg for food.