As trading got more popular more animals where traded rats would be infected with flees as to other animals they were infected also when the animals where killed or, the rats died from the flees they began to host on humans causing many people to die over the time period of The Black Death!
rats to fleas, fleas to humans, then human to human
It was carried by the fleas that lived on the rats.
the black death was carried by fleas that were on rats and the rats were on boats and they were carried over
Fleas on the backs of rats carried the black death.
the rats and fleas
The Black death was caused by fleas who were bourne on rats living on trade vessels essentially jumped ship at various ports
The Black Death was spread by fleas and rats. ik..gross
Fleas transmitted the disease from rats to humans.
Rats to fleas, fleas to humans
Fleas on rats
The Black Death was spread by fleas which lived on black rats.
The main carriers of the bubonic plague were fleas and rats. The fleas got it from the rats when they bit them. When the rats died, the fleas went to new hosts, bit them, and gave them plague in the process. Usually the new host was another rat, because rats hang together, but sometimes there was no rat to go to, and the fleas went to whatever animal they found.