The U.S. States with the Most Rodents

Illinois

Unfortunately, Illinois’ inclusion on this list is not a distinction. In 2023 Orkin Pest Control conducted research and determined Chicago, IL to be the “rattiest” city in the United States. In fact, 2023 was the ninth year in a row that the city earned this title.

Exposed garbage appears to be the culprit of rat infestations in large cities and the presence of rats isn’t just a disturbing nuisance. Rodents such as rats and mice multiply quickly and can cause extensive damage to homes with their teeth and burrowing. Rats also spread diseases including hantavirus, monkeypox, rat-bite fever, and salmonellosis.

California

Another one of America’s major cities, Los Angeles, CA has a rat issue of its own. Orkin moved L.A. up to the number two spot on its list of rattiest cities in America in 2023, while San Francisco ranked number five. However, California is a huge state and contains over 1 million acres of state parks.

With this in mind, it’s no surprise that the Golden State is home to a host of other rodents. Five species of tree squirrels make their home in California: the Northern flying squirrel, Douglas tree squirrel, Western gray squirrel, Eastern gray squirrel, and Eastern fox squirrel.

Ground squirrels and chipmunks also appear throughout the state. In fact, the World Population Review found that California has the second-largest chipmunk population out of all 50 U.S. states. Other rodents, such as the jerboa, are well adapted to living in the deserts of Southern California.

New York

New York has a bad reputation for its raging rat population. A 2023 study estimated that there are approximately three million rats in New York. Orkin ranked the state third in its list of rattiest cities for 2023.

Like Chicago, the culprit behind New York’s rat problem appears to be the large amounts of garbage in the streets. The city’s aging infrastructure only makes it easier for rats to invade homes and buildings, writes the New York Times.

Washington

Washington state features thousands of acres of parks, with about half of the state covered in forests. The World Population Review tied Washington for the number-one spot when ranking states for their squirrel population.

Washington also ranked in the top ten for the states with the highest chipmunk population. However, the Evergreen State isn’t just made up of forests. The state contains several large cities and Seattle typically ends up on Orkin’s list of top 50 rattiest cities. In 2023, Seattle ranked twelfth.

Oregon

Oregon is another heavily forested state. It tied with Washington in the World Population Review’s ranking of states with the most squirrels, while Portland ranked in Orkin’s list of top 50 rattiest cities.

Oregon is also home to a large population of one of the world’s largest rodents. Beavers are Oregon’s state animal and an important part of the state’s history. Though North America’s beaver population once dipped dangerously low, these large mammals’ numbers have risen back up to an estimated 15 million across the continent.

Texas

Two of Texas’ major cities (Houston and Dallas/Ft. Worth) ranked in Orix’s list of top 10 rattiest cities. Additionally, Terminex ranked Dallas/Ft. Worth number five on its list of most rodent-infested cities in the United States.

Finally, the World Population Review ranks Texas as the state with the third largest rat population in the country. Texas’ rodent population isn’t limited to rats. Prairie dogs can be found in the panhandle and western portion of the state. Other rodents, such as the Texas mouse and Texas pocket gopher, roam the Lone Star State.

Pennslyvania

Philadelphia ranked sixth in Orkin’s list of rattiest cities and third in Terminx’s list of most rodent-infested cities in the United States.

Additionally, Pennslyvania has found its way into the top ten of the World Population Review’s list of states with the most rats, squirrels, and chipmunks.

Finally, according to the Pennsylvania Game Commission, the Keystone State also has two native species of mice, four voles, a bog lemming, two types of jumping mice, and two imported European species.