Rats are usually blamed for the spread of the Black Death in Europe between the 14th and 19th Centuries.
The flees hidden in a rat’s fur are said to have carried the bubonic plague which killed millions.
However, biologist Nils Christian Stenseth, from the Centre for Ecological and Evolutionary Synthesis at University of Oslo, and colleagues now say the rodents may have been wrongly accused.
The scientists, when investigating 7,711 outbreaks of the disease, noticed each was preceded by weather conditions in Pakistan now associated with present-day plague incidents.
This suggests the Black Death erupted overseas and was brought to Europe by traders rather than surviving in European rat populations.
These climate events in Asia consistently preceded plague in Europe by about 15 years each time.
The research is published in PNAS (Proceedings of the National Academy of Sciences).
NOW WATCH: Briefing videos
Business Insider Emails & Alerts
Site highlights each day to your inbox.