Fleas: they're not all bad...

posted Dec 18, 2012, 12:15 AM by Professor Katz   [ updated Dec 18, 2012, 12:40 AM ]

Evil, Scary Flea (left)                              Nice, Friendly Rat (right)

As we learned, fleas played the most important part in the transmission of plague, and rats were victims as well, innocently providing transport.  The fleas carried plague bacteria, and their bites injected it into the bloodstream, causing infection.  The spread of the epidemic relied on two different rodent populations: one that was resistant to the disease and therefore carried it as hosts; and a second that lacked this resistance and died, passing over into Rat Heaven.  When the supply of rodent victims became too small, the fleas hopped over onto other hosts, including people, resulting in a human epidemic as folks got bitten and infected.

It's true that
some rats can cook.  But even fleas are not all bad. They have a circus: