You know as pet owner, rat owner.. I know rats as pets are great. But would never cuddle a wild rat!
You won't find many rat owners to disagree with the fact that yes their wild cousins are a plague and a pest. They are really successfull and..destructive.
Hell even as pet they are destructive..oh well.
I would say use steelwoll, yup already mentioned but if I noticed anything is that they don't like things that prick in their noses. Sensitive creatures
"'Tis true, 'tis pity, and pity 'tis 'tis true." -- Poloniouius, in Willie the Shake's _Hamlet, Prince of Darkness_