Magi, as the one who cast Color Spray (and like me, used it as effectively as possible :D) I allow you a choice: Do you want them to all make their own Will Saves or do you want me to make one big group save all or nothing? They have a Will Save mod of +1 as they are Dire Rats (these things are small, by the way, but they have 5 HP each), so how do you want to go about it?