how do i make mold infect yukkuri?
Simyukkuri is quite close to what happens in comics or text stories, so if you can't figure out how to do something, reading a comic or two is a good starting point.
Like, what are the living conditions of yukkuri with mold? It happens in humid places, sure, but also when koyukkuri don't do clean clean after poo poo.
What if you make yukkuri dirty?
Or even, what do yukkuri do with the stalk after giving birth? Isn't that a child yukkuri's first meal?
And so on.