In Europe the bubonic plague killed over 20 million people. The fleas on rats jumped of the rats and infected people and got them sick and then eventually they all died over time and these doctor wore these bird masks so they wouldn't sick because of the air and at that point they all thought it was either god or the air that caused them to die.
And so these things right these guys were the worst of it because they would spread it the most.
And so how you would know back then if you were infected was you would start seeing gigantic bumps.
The doctor would walk up to some people and touch them with the stick so they wouldn't get infected like the rest. And they would also put spices and minerals in there mask so they also wouldn't get infected because they thought the air was bad.
It killed over 20 million people in that time.
In this map it shows how and we're the disaster spreaded