Find Nemi in Ludibrium Village.
You met with Nemi again. The mice-trappers she made have gone rogue! Go defeat Ratz on Ludibrium: Eos Tower 100th Floor and collect 45 Mouse Traps to help her out.
I collected all the rat traps that Nemi needed in Ludibrium. I can't believe the amount of rat traps she made, judging from the fact that every single Ratz in Eos Tower is her creation.