The city of London struggled to control sanitation. As a result, __________ infested the streets of early London and contributed to the spread of the bubonic plague.
a. rats
b. snakes
c. locusts
d. leeches
The correct answer is letter A. Rats were the main cause of the Bubonic Plague which led to millions of deaths in Europe. These animals carry ticks that are infested with virus which thrive in filthy environments. The lack of proper waste disposal and sewage systems eventually led to the spread of the disease.