No. They thought that Jews were poisoning the water supply and/or that there was a "miasma" (something in the air) that was responsible.
yes
No more flea bites
rats carried flea's. the flea's carried the plague the people got the plague from the flea's but blamed the rats.
You are not technically responsible for what you don't know but, to some people you are.
Tomatoes... Thats all I know so far.
There are many species of flea - two local names I know of are chigger and sticktight
As a play (if that is what you mean), I don't know. As a song, the Russian composer Mussorgsky wrote "The Flea".
There was no medieval education for people other than nobility. People didn't know how to read or write. Priests taught nobility and a university system began in Italy.
In medieval times, I'm sure the Japanese ate sushi. Knights, kings, queens, and those kinds of people, didn't even know sushi existed.
There are natural ways to kill the fleas in your dog and one of them involves the use of Flea (be-gone) bag which smells good to people but it actually kills the fleas. You use the flea tub to ash it with the flea bag by sprinkling it.
Nope. All fleas are the same. There's no human flea, cat flea, dog flea, or any certain flea. They're on everything. A human could possibly get sick if they had a reaction to a flea bite (unlikely), but flea bites only itch. Trust me, I know. I attract fleas *and* mosquitoes, and all those other horrible things.
A medieval lord was the ruler of the land. The lord would make all the decisions.