nope not dying, just acclimating. my BTA does that,a nd infact when I first got it, it wouldn't even eat for two weeks. Now it has come out of hiding and eats every 3days or so. It shrivels up to expel waste and other reasons I don't know why like meowzer said. In fact mine did it today, found a silverside spine next to my BTA and it was shriveled. Now its back and I'll prob feed it tomorrow.