The pictures aren't clear enough to see what your talking about, but something "attached" isn't good. When were the pictures taken? Those chicks look like they just hatched. I
Not quite sure what it is, but I know it is NOT good. You can leave the chick in there I see if it goes away or is absorbed, but I doubt it. ----- sorry
I know this is hard, but if it were mine I'd destroy the chick. Chicks hatched like this that recover always have some sort of problems & a lot do not develop correctly & end up dying anyway