Fleas found guilty of spreading plague

A team of researchers, based at the University of Mainz in Germany, have confirmed that fleas were responsible for spreading the plague that wiped out over half of the population of 14th century Europe.

In their research, scientists studied skeletons discovered in pits near Hereford Cathedral. They found that that "the plague spread via the transmission of the bacteria Yersinia pestis, which was passed on through bites from fleas carried by black rats."