In Chapter 9, there is a notice outside of the Dining Room asking you to take care of 3 different rats for the Merchant. Two of them can be found during chapter 9, but the last one cannot be gotten until chapter 10, when Leon can go into the areas that Ashley opened.
- Dining Room – When you first enter, it’s running around between the Grand Hall and the actual dining area.
- Armory Exit – The hallway after the fight. It’s just after the cubic device treasure chest.
- Animal head hallway – West of the library. You first come here as Ashley.
The first rat you’ll most likely encounter is just past the notice in the Dining Room.
Rat #2 can be found as you exit the armory.
The last one can be found in Chapter 10 when you take Leon through the areas that Ashley opened up.