Apparantly it was quite common, during time of war, for soldiers and citizens to be driven to eating rats - especially during sieges. There are some accounts (during the Franco-Prussian war) of rat-sellers and one American journalist even writes about the best rat recepits and the comparisons between dog, cat, and rat meat.
Here is a painting by of a "Rat Seller"(c.1870)
Here is an account from 1871 by an American journalist, shut in in Paris during the Franco-Prussian war
...and another account of eating rats in Metz c. 1814