Rats cannot have been intermediate hosts for Yersinia pestis during medieval plague epidemics in Northern Europe

► Many plague epidemics (∼26) occurred in Norway in the medieval period. ► Bones assemblages show that the black rat only occurred in some harbour towns. ► We question the hypothesis that the black rat was the cause of plague in Norway. ► We hypothesize that plague was spread from human to human via an insect vector.