[This is animal planet shit. And Hershel nods with a frown at that.]

Maybe there are natural resistances? Also Heiji's been hurt but he's never been severely injured or starved the way Jake, Ema and Clive have. Alfendi fell into one after a serious injury too, though he seems fine now even though he's worse off. I suspect to some extent the more worn down and hurt you are the more likely it is to happen.

[He shrugs, really, all guesswork here. And more importantly-] I suppose it's possible the general public is unaware just how far technology has gone but I have to agree. This is all nearly the realm of science fiction, don't you think? It's a shame no one here seems to know more about this sort of thing... maybe Ema or Clive would.