dare I say it was a crappy episode? and that Fumiaki is a shithead?
actually, do moths actually poop that much? I didn't know moths even pooped (although they probably do, I think it depends on the diet and the digestive system...), let alone let out something their own size (south park Bono?).
to say it shortly, I suspected a bigger monster down at the moth lair.
as for Fumiaki, he's a despicable coward, but I guess him being a loser in the future makes it acceptable, as he didn't want any part of this, and they just sent him from his horrible poverty stricken life to one of unavoidable death.