It's absolutely living, makes the tank so much more interesting when it's out and abouthe looks like he is doing great =)
sometimes even ones you don't think will burrow will surprise you I came up onto my tank the other day and had to do a double take my 9" fire eel was buried and looked like his severed head was laying on the sand in front of my 13" fire eelI don't recall mine ever burrowing. I don't believe this species burrows.
hikari has jumbo bloodwormsIf you can buy some tiny earth worms I would try some of those as it will make it put on a growth spurt once you can get a bit more in to it. They seem to struggle with bigger foods the first time but then get stuck in. I also think you can buy super blood worm which is much bigger.
I expect you could soak those in with the ones he is feeding now and get it to take them too.s
hikari has jumbo bloodworms