So last week all of m babies were healthy and round

But today I saw one of them almost in bones, barely moving, I grabbed her and was like a rock then I saw the belly and looks like the top skin is a transparent layer...Uhmm, I don't know if I explained right, only on the belly, the rest seems to be fine, she ate only one piece, I thought she was thirsty but no luck.

It's only one with this problem, the rest is fine and eating very well (eartworms & fish) with calcium and vitamins