Weasels... What kind of folk are they?

I find the Winter War to be a very cool idea, and the notion that it’s not all over yet is appealing to me. I’m thinking about having my campaign center around trying to prevent WW2. However, since there haven’t been any weasels in the comics that I’ve read, I’m not certain how to run them. What kind of culture do they have? Are they more predatory and aggressive, or more deceptive and cunning?

And from a mission-planning standpoint, would a fight against a band of weasels be a Fight Mice or Fight Animal? Since weasels are intelligent, weapon-using folk, are they still treated as animals just because they’re not mice?