...When digging up a medieval floor for instance, you can pick out the bones of the same rat mixed up with other bones from animals eaten for food. All the rat's bones are there, though the left and right femurs are 3 metres apart. That means that when the rat died, its corpse was left there, entire on the kitchen floor. Nobody made the effort to throw it out of the window. Its bones were then then dispersed by people walking thorugh them. It shows that people didn't fear rats, they were used to them.
From an interview with the French archaeologist, crime writer and political campaigner Fred Vargas in New Scientist 312/07/04
(Incidentally - Fred is female)