As some city authorities said, we are clearly losing in a war with rats. We have lost for years.
A new survey published in the journal has strengthened the use of poison and traps, but the number of rats in places such as New York, San Francisco, and Toronto has recently increased. Progress of science. Researchers have analyzed rats and inspection reports in 16 cities that can use consistent long -term data. More than two -thirds of these cities have significantly increased witnesses for rats.
Washington DC has increased the largest witnesses in the past decade, according to a survey, which has been the most comprehensive rat of urban rats.
“We are holding the heels and are pushed backwards,” said Richmond's research and ecologist, Jonathan Richardson, about the fight against Rat's invasion.
There are even worse news. This study shows that there is a strong connection between the increase in rats, which is the result of climate change, and the rise in temperature. Research has discovered that rat witnesses have increased significantly in the faster and warmer cities. This is because when winter gets warmer, rats spend a lot of time and breeding, reducing the time to dive underground.
Scientists predict that urban areas will be warm at 3.4 to 7.9 degrees by the end of the century, depending on the amount of combustion. Cities tend to be hotter than rural areas -Concrete and other human infrastructure absorb more heat than vegetation -faster and warmer. In other words, it means that the current rat control method is not only failed, but the problem is much worse.
Therefore, it is good to have a clear solution. Even better, it's easier.
A city where rats are growing the fastest witnesses
Rats are the most common urban mammals, but they don't really know if they actually have them. They do not carry out rat census, for example, like squirrels. For this reason, researchers depend on 311 complaints instead of how the population is changing. These complaints have been shown to be correlated with the abundance of rats, but they are incomplete approximation. Beyond a huge number of rats, many factors affect whether someone complains, relationships with landlords and trust in the city government.
The new research depends on these general complaints, but also uses an inspection report created by city authorities that inspect rats as part of complaints or as part of aggressive sweeping. The author has identified 16 cities that have consistently reported this data for at least seven years.
The figure below shows how the witnesses of those cities have changed. A city with a red bar indicates an increase in rats. Longer bars increase significantly. In contrast, the blue bar indicates that rats are declining. The take -out is that DC, San Francisco, Toronto, and New York City have seen a surge of witnesses in the past few years, while the witnesses of rats in New Orleans and Tokyo have declined.
Richardson et al. , 2025
Researchers also investigate what they may be promoting these trends, and ultimately link the rat witness to the temperature, the degree of urbanization (that is, the lack of green spaces), and the population density. Ta.
This is not particularly surprising. When it's cold, rats and other small mammals dig a hole underground and get warm. “This is called vertical movement,” said Michael Parsons, a rat expert in urban ecology scholars. “They continue to be deeper and deeper as they get colder, as they do, they are not mating.”
Parsons said, the founder of the Urban Ecology Consulting Company Center, said that they didn't eat so much. When the temperature is low, the food smells so much that it is difficult for rats that rely on the nose to find the next meal. (Not only cute, but as a terrible thing, rats seem to breathe each other and decide on their favorite food.)
In summary, this means that as the city gets warmer, the rat can eat and mate for a long time, making it easier to find food. Parsons said this could help New Orleans to explain why rats did not increase. The cities already have a warm and subtropical climate, so additional warming can make much profit to rats. According to Richardson, too hot fever could ultimately a problem, but rodents seem to be more restricted by heat than cold.
“For centuries in New York City for several decades and decades, we have relied on cold winter snaps to support population control,” said New York. Director Cathleen Corady states. “We have a continuously warm winter. We know the impact on these groups.”
On the other hand, research has discovered that rats have increased in cities with fewer green spaces (meaning more buildings and urbanization) and high -density of people. Probably because human infrastructure, such as homes and restaurants, is a more set food source compared to large parks. This is because the land and population of cities living in the city is expected to grow in the next few years.
Basically, the future is becoming more Latier.
Why is it so bad for humans to control rats?
In short, more rats are not great. These animals can carry dozens of pathogens and parasites, such as a hand viral pulmonary syndrome and a bug that causes severe pulmonary diseases.
There are also many studies that link rat infection to mental illness, such as depression and psychological trauma. Recent studies in Chicago showed that those who saw rats almost every day or almost every day would report the serious symptoms of depression. And poor areas often have more rats, so they tend to stand on the arrow of these problems.
There are several very important reasons to reduce the number of rats.
However, despite the decades of anti -rats, which cost hundreds of millions of dollars, the invasion in many major cities has deteriorated. In some cases, it's much worse. Why aren't we, human -sized brain and human skills doing better work to control these animals?
One of the questions is that in most of the previous century, the city has rely on the traps and bait traps to eradicate rats.
This approach does not work.
According to Jason Munshi South, an ecologist and rat expert at the University of Drexel,: “What we do is killing rats at a local level, so you feel like you're doing something, but you oppose the brutal mathematics of the ghost of rodents. “
The well -grown mother, Nay, can give birth to more than 10 babies in garbage and have several liter a year. Furthermore, poison did not reach all rats, and some people learned to avoid it.
Poison Do It often causes rats terrible death and often leads to long -term internal bleeding -it kills other wildlife. When scientists collect dead birds, they find dentures in most of them. “Dying dentures like an anticoagulant is a terrible way to die,” said Munshi South.
According to Richard Song, pests continue to depend on poison and bait. “They just do the ability to do it in a practical and short time frame,” he said.
At present, it is also making benefits in the extinct industry.
“The exterminator is not paid to completely remove the gaps,” said the Parsons. “They are paid to control rodents, they are always needed. I am not ironic at all. This is a way to work.”
This actually works
There is only one way to remove rats. Please put out garbage from the street. It is literally.
“It's not a rocket science,” Richardson said. “We know what we need to do.”
To control the rats, you need to put garbage on the top and sturdy bottle that the rats cannot be easily chewed without entering the curb bag. It demands that people do not hold garbage. Cleaning is required.
However, it is a challenge to fine -tune the norms of the huge cities and the norms of behavior. Cities or buildings may need to purchase and maintain a new bottle. The garbage collection may need to fine -tune the operation and use a new truck. Residents may need to be educated for appropriate disposal. To create a large waste bottle space, you may need to remove the parking lot. Several urban institutions, such as health, hygiene, and housing departments, may need to be involved. “It's not as easy as it looks,” said Munshi South.
But this approach is clearly functioning. Definitely, New York, the most famous rat city (a famous rat celebrity), has recently demanded that most of the cities are placed in a container with a safe lid instead of plastic bags on the street. progress! According to Richard Song, the spare data suggests that these changes may already be dented by rat complaints.
Under the administration of the mayor of Eric Adams, Coradi told VOX that the so -called containerization is a “characteristic” of the battle of the city with rats. “We are very optimistic and excited about seeing the rollout and its rats because the food source has been prosperous for a long time in New York and other urban areas,” he said. I did it.
The decrease in witnesses in Tokyo in Tokyo may also be related to containing food waste. According to Richardson, urban culture has a lot of value in hygiene. When people found rats nearby, restaurants and other businesses became embarrassing, and the growth of social media became easier to embarrass. Japan is also developing other anti -rat approaches, such as injecting the smell of herbs and injecting them into garbage bags.
New Orleans had a similar story, which saw a sudden decrease in witnesses. Richardson said that the city has been working a lot in residents and government agencies about the actions that support rats, such as excluding garbage and debris.
Eventually, Corradi fixes rat invasion is that “rat problem is a human problem.” In the first place, it is human behavior that enables rats to prosper.
In other words, Parsons said that Rat was not responsible.
“The rat is in the northern part of Mongolia, which is hanging in the burrow, without these food bread crumbs that have fallen throughout the continent,” he said. “We kill another species, kill it, and in some cases torture it.
“It's just enough [research] He needs to stop being a field bar in an animal approach, “he said. “They deserve basic welfare.”
