Part 1: Introduction to Rats in America

Norwegian Rat

Throughout most of American history, one typically would associate rats as the typical urban pest.  People typically associate rats with the dark, dirty parts of the cities, which for the most part is true.  Nevertheless, rats have become a part of the environment of urban landscape.  Which is not necessarily a good thing.  Rats are associated with carrying disease and causing damage.  For all of history rats have been a very negative part of city environments and have been primary hosts for countless diseases.


Through this blog, I will be exploring many different topics about rats and how they have affected, and continue to affect, the environments of the cities across America.  Rats have not always been in the Americas, how did they get here?  How have rats transmitted diseases in cities?  Why have they thrived in the Americas?  How did rats diffused so quickly across the world?  How are cities trying to combat the rat populations?  Who was the Rat King?  These are just a few of the questions I started with and I endeavor to answer by the conclusion of this blog series.


In class, we are pushing into the 20th century and have discussed on multiple occasions diseases and how they have affected America.  I remember on the first or second class it was briefly mentioned about how rats have been an interesting part of the environment, which originally sparked my interest.  However, we have not really touched upon how these diseases have been spread; a source for cities at least is mainly rats.  To me, it is interesting how a species, which originally was not present in the Americas, but now, is the most prominent pest in American cities.


Before I begin to answer the aforementioned questions, I believe rats need to be discussed more as a species in general.  According to Sullivan, the Rattus norvegicus, more commonly known as the Norway or brown rat, is the most common species of rat found in American cities, especially New York City.  The Norway rat is described as a stocky, grey or brown rat with two sharp yellow incisors.  These rats typically dig tunnels to their nests and to help them navigate around the city, while other rats are found typically where their name suggests, for example sewer rats and alley rats.  When not found digging, they are typically found gnawing or feeding on trash, wires, and plants.  This can cause many problems in an urban environment in which most of everything we use today runs off electricity, which requires wiring, a favorite of rats to gnaw on and destroy.


As mentioned previously, rats are not native to the Americas.  Their roots can be followed back to Asia where they then spread across Asia and then eventually to Europe.  By 1800, the Norway rat had settled most of Europe.  They were then brought to the Americas via ships bringing people and supplies, and by 1926, they were in every single state in the United States.  The Norway rat eventually pushed out almost every other type of rat from cities in the Americas, including the Black rat.  Now these two species of rats only cohabitate in certain areas; including Southern port cities and California, where they can nest in other places such as palm trees.


In the subsequent blog posts, I wish to delve deeper into the role rats pay in the environments of cities.  I want to explore the different kinds of diseases rats carry directly as well as indirectly.  How rats have diffused across the world so rapidly.  How much damage do rats cause in cities, as well as who is responsible for maintaining the things they destroy.  How cities try to monitor and reduce the rat populations as well as what has made the rat population the dominant species of rodent.  In addition, I wish to discuss the history of rat fights and the underground system of betting that was involved with the fights.  Another interesting topic that will be discussed is the difference in rats and squirrels, both of which are rodents, but one is considered a pest that needs to be killed while the latter is seen in a much better light.




Picture from:


Sullivan, Robert.  Rats: Observations on the History and Habitat of the City’s Most Unwanted Inhabitants.  Bloomsbury Publishing, 2008.

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