No, rats never carried plague. It was the fleas that they carried. Domesticated rats don't have fleas. Even wild rats are very clean and any fleas they do have don't carry plague much anymore.
Bubonic plague and Cat Scratch disease can be carried by fleas.
They can and sometimes do, although it is the fleas on them that actually carry the diesease.
Fleas carry the bacterium Yersinia pestis, formerly known as Pasteurella pestis. The plague bacillus can be stained with Giemsa stain and typically looks like a safety pin under the microscope.
http://www.themiddleages.net/plague.html Rats / mice can carry fleas that carry the "Black Death" or bubonic plague.
The Black death was killing people by ships having rats and fleas. Then the fleas carry the plague and then the fleas go on the people and then they will get sick and die.
With the discovery of cells and microbes hundreds of years later, the plague was discovered for what it truly was, shortly afterward scientists discovered the origins of the plague (the fleas and rats) and were then equipped with the knowledge to fight the plague.
The plague was carried by rats, who were infested by fleas. As the rats succumbed to the plague, the starving fleas fed on humans infecting them with the plague.
The carrier of this plague is the rats the carrier of the plague is actually fleas and ticks because they bite the rats and give them the plague. So the carriers of the plague are most rodents, ticks, and fleas.
Fleas can transmit heart worm, tapeworm, etc. to your animals. Fleas are tiny, but they sure can pass things on to your animal that you wouldn't want. The best thing you can do is always keep up on the flea treatment and preventatives.
The plague is caused by the bacterium Yersinia pestis, which is carried by fleas, which were carried by rats.
fleas on that live rats its not the fleas it was the blueberries