@Mant A little after fractured humans became acknowledge by society, pharmaceutical companies, led by one of Jagaaan's former teammate, managed to create artificial dung balls.
It was around chapter 50, right after the first climax iirc.
@Mant I believe the dung ball is only meant for full fractured humans with bird companions. HFH don't have to worry about the dung balls; maybe the trade off is that hfh tend to be weaker compared to their full fh counterparts.
FFH seem to always be designed for combat in some way shape or form; probably to fulfill their duty of destroying the froglets, while hfh literally care only about the host's desires even if it adds no benefits in combat.
Of course not. Nor where the frogs originally came from. This manga started as essentially a trope parody. We probably won't get any explanations until the very, very end.