Because it wasn't exactly the rats. It was the fleas on the rats, so it killed the rats and then the fleas moved onto a person who was either warm or alive. And they also knew that it was the rats because the rats were little stowaways on ships going to Europe.
Actually, people in the Middle Ages did not know what caused the plague. They thought people who got sick had sinned against God, or that the Devil made people sick, or perhaps it was "bad air." Back then, nobody understood the connection between rats/fleas and sickness - they used their rivers and streets as sewers, drank contaminated water, and thought that fresh air and bathing were harmful. People in the Middle Ages did exactly the wrong things, and spread the Black Death across the known world, killing millions.
Some people thought that an unusual positioning of Mars, Jupiter and Saturn had caused the plague. Others in Europe blamed the Jews, and many people pointed to witches. The UK was almost entierly Christian at the time, so they mostly went for witches and strangers as far as outsiders causing the plague was concerned.
Medieval people had three main thoughts of the cause of the plague: god, air and Jews. Some believed that God was angry with them because of their sins so he sent down the plague if this was what they believed they would whip themselves to stop the plague spreading. Others thought that everything was in result of the four elements (earth, fire, water and air) in the case of the plague it was the unclean air this would be solved by cleaning out the streets. Others would blame minority groups for reassurance, in this case it was the Jews. Many Jews were burnt during the time of the plague.
The fleas that were on the rats carried the plague bacilllus (Yersinia pestis) and when the fleas bit people, they became infected.
* smells * Invisible fumes in the air * Bodies humors were out of balance * Movement Of Stars And Planets * God and the devils * The Jews poisoning water supplies
They thought it was opal but it was diseases carried by rats
During the black death the rats played a important part because they were the ones that spread the whole disease.
rats got infected by Yersinia pestis bacterium. When they die fleas spread bacteria to humans.
Itvwas cOmmonly known as the black plauge or black death but it was really the bubonic plague and it staryed in Europe from fleas in 1347
China
It effected most of the body, more of the central part. Its said to say that the Black Death started by animals suddenly dying by unknown causes. The Black Plague spread by ticks,mits, and rats. So mostly the arms body and legs.
The first part of Europe affected was Messina, Sicily in October 1347 when a ship avoided the Messinians, rats carrying the virus spread it throughout Sicily and then on into Europe.
Nearly 2,000 spread around the Mediterranean and Black Seas.
Eamonn Walker
The Aztec culture spread over great areas.
All parts of a space suit are important, if any part fails it can lead to the death of the astronaut.
The church was a major part in explaining the black death. This is because they thought that God was punishing all the bad people in England. So when it wiped out most of the town, including the good people, they where constantly praying and telling God that they were good people and they didn't deserve to die.
Answerthey were exposed to the disease Different answer:There is a theory that the Black Death was caused in part by anthrax. In that case, anthrax would almost certainly have been the cause of death for the sheep and cattle.
The Black Death arrived in Europe from the east. The first part of Europe for the epidemic to break out in was Sicily, the island off southern Italy. So we can probably conclude that Palermo in Sicily was the first European city to become infected with the Black Death, although did not start it.