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Baltimore has fewer rats than D.C., and other important facts about the city’s long history fighting rodents

A rat forages for sunflower seeds.

It’s true: Baltimore ranked No. 9 on Orkin’s list of American cities with the worst rat problems in 2018.

But so is this: Washington, D.C., ranked No. 4.


President Donald Trump’s tweets attacking U.S. Rep. Elijah Cummings and calling his 7th District “disgusting, rat and rodent infested” spurred outrage on Twitter. But some observers noted that Baltimore does indeed struggle with rats.

While Baltimore’s rat population seems to have decreased in recent years, experts say the neighborhoods struggling with rodents are often victims of poverty, discriminatory housing policies and problematic urban planning.


The city’s relationship with rats was the subject of Baltimore filmmaker Theo Anthony’s 2017 documentary “Rat Film.” The film touches on the way the city’s infestation intersects with segregation, poverty and other racist policies. Anthony declined a request for an interview Monday.

In the film, Anthony explores how some of the poor and rat-plagued sections of Baltimore were historically “redlined," the practice in which banks and insurance companies barred investment and lending in many nonwhite neighborhoods.

In Baltimore, the practice created a major hurdle to prosperity for many people; the city was also first in the nation to pass a residential segregation law, restricting blacks and whites to certain sections of the city. While redlining was banned more than 50 years ago, a 2019 report from the Urban Institute found that many racist policies of the past continue to hurt Baltimore’s poorer African American neighborhoods.

Dawn Biehler, an associate professor at the University of Maryland, Baltimore County, who has researched the history and public health impact of rats in Baltimore, said the root of rodent problems in any city is poorly maintained housing stock. And for that, she blamed a lack of housing code enforcement, particularly in poor neighborhoods already affected by decades of discrimination and disinvestment.

“If codes are poorly enforced, rats have more places to hide,” Biehler said.

Those problems often aren’t under the control of residents, who are at the mercy of absentee landlords and housing enforcers, Biehler said.

[Some residents are] afraid to go out at night because there might be rats lurking around. It kind of makes them feel like they’ve been treated as trash.”

—  Dawn Biehler, associate professor at the University of Maryland, Baltimore County

Gregory Glass spent 30 years watching rats scurry down Baltimore alleys, as a public health researcher at Johns Hopkins University. He said he could reliably find rodents in alleys in East and West Baltimore. But even there, he said, he often didn’t find them living in more than one out of every four houses.

Glass said the design of Baltimore neighborhoods — with secluded alleys where trash can pile up — allowed rat populations to take root more than a century ago. Absentee landlords have made the problem worse.


“Baltimore definitely has issues with rats. It’s not in Representative Cummings’ district, necessarily,” he said. “It’s certainly not worse than in D.C.”

These days, the city’s Department of Public Works operates a rat eradication program, which saw its rat-fighting crew doubled in 2014.

Under a $10 million program launched in 2015, all Baltimore households were given a sturdy, 65-gallon trash can on wheels to better control the rat population. And in 2017, then-Mayor Catherine Pugh announced plans to rid Baltimore’s thousands of public housing units of rats.

The most common rat in Baltimore is the Norway rat, also known as the brown rat. Baltimore has waged “wars” on these rodents for more than a century in a variety of neighborhoods.

In 1883, The Sun reported a group of about 50 men gathered in a rat pit on Lexington Street and watched dogs, ferrets and other animals kill Norway rats.

Throughout the 20th century, Baltimore adopted a variety of creative techniques to address the rat population. In 1973, officials armed inmates at the city jail with sticks, giving them free range to combat a serious infestation. A few years later, city officials used cash prizes and gift certificates to motivate residents to compete for “the cleanest block.” In 1987, Remington neighbors declared a victory in the war against its rats and threw a “rat bash” in which children beat a rat-shaped piñata named “Ratso.”


Baltimore was also one of three cities in 1979 to receive 10-year funding from the U.S. Department of Health, Education and Welfare for rat eradication. The grant awarded Baltimore $280,000, to which the city added $200,000. The money was used on two large swaths of East and West Baltimore.

Of course, the rats have won their own fair share of wars over the years. In 1934, a statistician reported to The Sun that Baltimore likely had more rats than people. And Baltimore’s Independence Bicentennial birthday cake — designed to land the city in “The Guinness Book of Records” — became a political embarrassment when it was stored improperly and ruined by rats, mildew and mold.

Rat-borne disease is less of a public health problem than it once was, but rodent populations still wear on communities. Based on conversations with residents of West Baltimore, where Biehler has conducted rat research, the professor called the rodents a constant stress on residents and a drag on their quality of life.

“They’re afraid to go out at night because there might be rats lurking around,” she said. “It kind of makes them feel like they’ve been treated as trash.”

Rat bites were once a significant enough public health threat to prompt Johns Hopkins research on the spread of polio and rabies. In a study published in the Journal of American Medicine in 1947, Dr. Curt P. Richter called rat bites “a hitherto overlooked means of transmission of such diseases.” The study found that 65 people were treated at Johns Hopkins Hospital for rat bites from 1939 to 1943.

The Morning Sun


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But the prominent journal's editors noted that the health effects were likely no greater in Baltimore than in any other city, or even on farms.


Richter was credited with leading the charge against the city’s rat population in the 1940s, developing a poison that a pound of was said to be potent enough to kill 300,000 of the rodents.

Other Hopkins research into the behaviors of rat colonies soon proved more effective, though. Efforts to break up rat burrows, cut off their supply of food from garbage and rat-proof homes was said to shrink rat populations by 80 percent in some neighborhoods in 1948.

But that didn't mean the city's rat problem was solved.

Among public researchers, Baltimore’s rats have maintained a distinctive reputation ever since. Gregory Glass, a former Hopkins researcher who is now a professor at the University of Florida, told The Sun in 2009 that the 1940s research is still frequently cited in the field.

“People from New York are always asking me to send pieces of Baltimore rats to them,” he told The Sun. “I think, ‘You’re in New York — you have your own rats.’”

Baltimore Sun reporter Chris Kaltenbach and staff librarian Paul McCardell contributed to this article.