- It is a bacterium that has in many forms destroyed millions of lives by causing epidemics. This includes the sixth century Plague of Justinian, the Black Death that killed nearly 1/3rd of European population, and the Third Pandemic in the 19th century.
- Y. pestis has been used as a biological weapon in World War II when Japanese airplane released rice and wheat plus rat fleas carrying Y. pestis in China leading to a local plague that killed 121 people.