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Brian Lehrer: Brian Lehrer on WNYC. Now we'll speak with the woman in charge of addressing one of New York's pressing concerns: rats. We've all got a rat sighting story, right? Maybe one ran across your foot on your walk home or made a nest out of your car engine. If you're really unlucky, maybe you encountered a rat in your toilet or in your subway car. One rat encounter has been making headlines in New York City's newspapers this month. A woman at Wild West playground near Central Park West, 93rd Street entrance, saw two or three rats hop out of her children's stroller as she was getting ready to leave.

Rachel Chase, the unlucky Upper West Side mom, told The New York Times that she wanted to "set the stroller on fire" after the incident. A relatable sentiment for anyone whose personal belongings, never mind potentially your kids, have ever made contact with a dreaded creature. This incident shed light on a larger problem on the Upper West Side in particular, and possibly for some playgrounds, per se. Have you seen the photo circulated by the New York Post of two dozen rats feasting away on food scraps left for pigeons at the median on Broadway near 96th Street?

Earlier this year, rat sightings were down. The city's rat czar, Kathleen Corradi, told The Times that 311 complaints in January dropped by 24% in comparison to last year. That's after they implemented some anti-rat measures in the Adams administration, you may remember. What's the state of New York City's rat population now, and what about those playgrounds? The rat czar herself, Kathleen Corradi, whose official title is Citywide Director of Rodent Mitigation, is with us to hear your concerns. Director Corradi, welcome to WNYC. Thank you for doing this.

Kathleen Corradi: Good morning, Brian. Thanks for having me.

Brian Lehrer: Listeners, we can take some phone calls. Anybody seeing a late summer infestation, as it's been called in playgrounds on the Upper West Side or any playgrounds, or that swarm at the median at 96th and Broadway, or is there an issue in your neighborhood that hasn't made the press yet that you would like the rats czar to pay attention to? 212-433-WNYC. Call or text, 212-433-9692. Help us get an understanding of the scope of this issue, Ms. Corradi. Is there a rat census? Do we know how many rats live amongst us across the five boroughs?

Kathleen Corradi: It's a great question, Brian, and one that's asked frequently. We do not have a rat census, we don't have a population count, but what we do have is really good information on rat burden, where we have neighborhoods where there's more rat activity, more conditions conducive to rats. We know that through a couple of metrics. One is looking at our complaint data, our 301 complaint data. As you notice, that's something we're seeing a decline in rat sightings in.

Then secondly, through our department of health inspections. That's we have a trained inspector go out both in response to complaints and proactively across our city. What they're looking for is conditions that support rats, litter, uncontained garbage, harborage conditions, or active rat signs. Through those, we are really able to understand where in the city we have this higher rat burden, where we can focus efforts, and where we can work with property owners to address those issues. I would encourage everyone here to check out nyc.gov/rats and look at the Department of Health rat portal.

You can actually look up real-time inspection data from the Department of Health and see, has your local park been inspected. Is that property across the street inspected, and then see the findings from the Department of Health to either validate, yes, there's rat activity, the health department is taking action with that property owner, or there's been no complaints filed. Let me make sure I call 311 and report that.

Brian Lehrer: A lot of New Yorkers know that you went not that long ago to a trash containerization policy. Instead of putting out the trash for collection by the sanitation department in plastic bags, it's got to be in these sealed containers now. Has that made a difference that you can measure?

Kathleen Corradi: The Norway rat, which is our species of rat in New York City, Rattus norvegicus, only needs one ounce of food a day to survive. What the science tells us is a well-fed rat is a rat that has the ability to reproduce at uncontrollable rates. By containerizing waste, cutting off their access to food, we're really stepping into integrated pest management and thinking about front of the equation impacts that we can do to stop rats' ability to reproduce. We're seeing really great success containerization city-wide and also in CB9 in Harlem, where we have the first ever fully containerized community board, both from rat sightings, but then also from our Department of Health inspections.

It's too early to declare full success. We really like to lead with evidence-based work, but we're seeing really good trends. We know the science says taking away food source is how we get to sustained reduction, and that's our goal across the city.

Brian Lehrer: You can imagine the calls are streaming in for you. We're going to get to the playground issue in a minute, but we were just talking about containerization. Jonathan, Sunset Park is calling with, I think, a way that some people wind up neutralizing that advantage. Hi, Jonathan, you're on WNYC.

Jonathan: Hi, Brian. What I wanted to say is that the city has made these regulations that say you can't put your garbage out until 8:00 PM. I live across the street from Sunset Park, where there are a lot of Latino immigrants who love to party. Every night they're out there partying, and there's barbecues and there's food and picnics and parties. Then, when they get finished, some of them just dump the garbage anywhere.

Most of the people who want to do the right thing they're putting the garbage in the garbage cans. There are not enough garbage cans. The garbage overflows. There's bags of garbage and all kinds of stuff lying on the ground. Even the garbage cans are not covered. If the stuff is in there, rats can get in there, and there are rats running all over the park. I go out there every night, and this park, there's rats everywhere. I see this is just very typical of the way City attacks problems, is that you make mandates for the citizens to follow, and then the City does not adopt the same policies. I could go on about a lot of other things.

Brian Lehrer: Let me jump in and get a response for you. Obviously, if you think, Ms. Corradi, that Jonathan is pointing up a real problem, of course, Sunset Park is not the only place in New York City where people party. Have you noticed that?

Kathleen Corradi: Yes, absolutely. Thank you, Jonathan. We work really closely with the Parks Department. We take a whole city approach. We have a task force that meets with over 40 offices and agencies, and Parks is a key stakeholder in that. Jonathan, you've hit the nail on the head. Our parks are some of our busiest spaces, and when we're thinking about our rat mitigation work as a city, you're absolutely right. We are thinking, how do we make sure our city-owned and city-managed properties are doing the best practices that we're asking our neighbors to do as well? That's containerizing garbage.

Parks in particular has, during the busier months, a second shift program where they have staff coming later in the day to help with some of that litter, help with some of that waste removal. We really need the public bought into and making sure that they're treating the park like it's their own backyard, and making sure litter gets in the right place, reporting cleanliness issues, and working together to address these. We're working citywide to containerize our waste on city-owned properties, just like we're asking our neighbors to do on private properties.

Brian Lehrer: He frames it in terms of park, is that related to playgrounds, and are playgrounds in general particular rat hotspots?

Kathleen Corradi: Our species of rat, Norway rat, Rattus norvegicus, is a burrowing animal. Their preferred habitat is nice, rich, healthy soil. All the work that goes into keeping our parks and green spaces beautiful parks and green spaces also makes it an ideal habitat for the Norway rat. When you add in access to food, whether that's from barbecuing, overflowing litter baskets, or a candy wrapper that's been left behind at a playground, you've created the ideal habitat for this animal.

What we want to do is we work with Parks very closely to make sure that we're removing harboring conditions, conditions like a lot of leaf litter, low-lying plants that can encourage rat burrowing in those areas, and then working with Parks' operation, but also the general public to make sure we're limiting that food source. One thing that we've done is launched the New York City Rat Pack. That program is just over a year old.

What that does is that invites New Yorkers into the conversation through education, advocacy, and action, and ask them to better understand this animal, better understand human behaviors, and then work alongside the city, work all together in community to address issues in their blocks, their parks, and their playgrounds.

Brian Lehrer: Jacob in Brooklyn, you're on WNYC with the rats czar, Kathleen Corradi. Hi, Jacob.

Jacob: Thank you for taking my call. I have a question, and I have a tip as well. The question is, how can businesses utilize the services that the city provides? The tip is for homeowners, really, and those that live in apartments. I thank God that I have not seen mice in over three years, since 2022. What I did was I renovated my apartment. I found every possible gap and entrance for mice, and then what I did was I plugged it with steel wool, and then I just reinforced it with expandable foam.

What happens is when you put the expandable foam with the steel wool, it'll basically cover all the gaps, and then that way it's going to be impossible for any mice to get in. I would advise all New Yorkers to do this. Very [crosstalk]

Brian Lehrer: That's a tip for people in their apartments, but your question was about businesses, how come?

Jacob: Because I started a business with friends of mine, and basically they-- We had our neighbor, they came to us, they were like "Oh, we have a rat problem." They wanted to see if we can try fix it. I was trying to see if there was any kind of service from the city to help them-

Brian Lehrer: Jacob, thank you.

Jacob: -prevent any future problems.

Brian Lehrer: Advice or offers, Ms. Corradi?

Kathleen Corradi: We absolutely want to make sure we're working with all New Yorkers, including businesses. There's a couple of educational opportunities for business who are either in the pest management professional world or just in New Yorkers through our rat academies. We have a professional rat academy for pest control professionals, and then we have one for the general public. That's a great way to learn more about this animal and what you can do to prevent them on your property.

For our city-managed sites, for a lot of our spaces, schools, parks, New York City Housing Authority, we actually have city staff that works on integrated pest management, and then there is some contracted work out that's all done through citywide contracts. Jacob, those are things you can explore through the city procurement if you're looking to work with the city more formally. For everybody, we want you aware, educated, and we have great opportunities for folks to learn more about rat prevention.

Brian Lehrer: A listener texts, "Can you do some kind of rat birth control?" Maybe the religious right would be opposed, I don't know, but hahaha. Seriously, can you do rat birth control? Is there such a thing?

Kathleen Corradi: There is such a thing, Brian, and actually right now the Department of Health is running a pilot in Community Board 9 per legislation that was put out of city council earlier this year, where they're doing a one-year pilot to try three different contraceptive methods for New York City rats. They're using evidence, science-based. In about now 10 months, we'll have the findings of that, and folks who are interested in can learn about more about the products that are being tested on nyc.gov/rat.

The piece I'll say about this animal and all commensal rodents control, whether that's through extermination or contraceptive, can only get the tip of the iceberg. What the science tells us is we need to be addressing those underlying issues, food sources, places they're living, which are mostly driven by human behavior, if we want to lower the carrying capacity of an area and get to sustained reduction, which is the resilient and long-term goal of how you reduce a pest population.

Brian Lehrer: Curtis Sliwa, the Republican candidate for mayor, who is a big cat person, he keeps many cats. He's running in part on ending cruelty to animals, though not necessarily being really nice to rats platform. He has suggested unleashing cat colonies where there are rats, including at playgrounds. Have you heard that, and do you have a reaction to it?

Kathleen Corradi: I have heard that, and that's something often shared as a potential solution, but there is some really famous, scientifically peer-reviewed journals out of Baltimore in the '50s and '60s. What they found is that if there are ample resources, read that as food sources for cats or other pests, that cats are not a control mechanism for rats. It is not a silver bullet. Last September, we held a national urban rat summit. We brought together leading rodentologists, those are PhDs who study urban rats and other municipalities, to make sure we're really leading with what the science says. Right now, science does not back that cats are a control or deterrent method to the Norway rat.

Brian Lehrer: Peter in Brooklyn, a community gardener. Peter, you're on WNYC. Hello.

Peter: Hi there. I am a community gardener in Bed Stuy Hart to Hart Garden. It's a GreenThumb garden that's supported by the city parks department, which we really love. You mentioned Norway rats burrow in nutrient-rich soil. We are trying to keep our soil nutrient-rich and mitigate lead. The previous caller, two callers ago, mentioned expandable foam as a solution in apartments. I totally agree, but we are outdoors, and so we have done a ton of work in the garden to mitigate rats by basically fixing infrastructure and constantly filling holes with gravel.

We deeply appreciate the support given by the city through our GreenThumb rep, Greg. The city sends an exterminator who's a nice guy. I believe he's a contractor, and he uses expandable foam outside. I see this in parks, and in my experience, it is not a long-term solution outside. The rats destroy it in a night if they want to. The little crusties of this plasticky material get everywhere, or they burrow around it and use the foam as a roof. That makes it harder to destroy subsequent burrows. When is more substantial support, the birth control, the shooting CO2, when is that coming to GreenThumb Community Gardens and parks?

Brian Lehrer: Peter, can I ask you a quick follow-up, and then Ms. Corradi can respond?

Peter: Yes.

Brian Lehrer: How do you feel about rat poison?

Peter: It doesn't seem like a long-term solution because they get used to it. That's what I heard. It'll work for a year. I believe they've baited the garden at times when we've been desperate. We've seen more success by just being really consistent. Filling burrows, denying them shelter. That's my take.

Brian Lehrer: Thank you. Ms. Corradi, anything you can offer Peter at the community garden in Bed Stuy?

Kathleen Corradi: Peter, I'd say first for your specific garden, please reach out to GreenThumb, and we can leave loop in with that team. The Department of Health historically has done some supportive work with GreenThumb and Community Gardens and has prioritized the use of carbon monoxide extermination, so non-rodenticide method of control. We can speak offline about that, reaching out through GreenThumb.

You're absolutely right. Foam is a great tool for mice, but it is penetrable by rats. In outdoor exclusion, what we actually recommend is something like a wire lathe that you can bury under 6 to 8 inches of soil. That makes it so your plants can grow, keep soil healthy, but it can prevent the rats from burrowing in garden beds and planted areas. As a city, we are always looking for ways to prioritize non-rodenticide treatments, whether that's carbon monoxide or carbon dioxide, or burrow harassment, Peter, which you were talking about, making it more and more stressful for rats to live in the area.

All of our city agencies who do extermination are utilizing those treatments, and that's certainly something we're trying to work to expand. We think it's a great method of control. Then work with private pest management companies to make sure that they're trained and educated and have a whole toolkit at their disposal if they're working on private properties or contracting for the city.

Brian Lehrer: On rat poison, I feel like I see signs in lots of places around the city, warning, there's rat poison in this area. Flaco, the owl, died by ingesting rat poison, I believe, correct me if I'm wrong. What is the proper use of that? Then just tell people how they should contact your department if they want particular kinds of help, and then we're out of time.

Kathleen Corradi: Great. Brian, the use of rodenticides, which are mostly anticoagulants, have been found in other animals, and there's some new research coming out about secondary poisoning effects of that. As you mentioned, with Flaco, the owl where rodenticides were found in the body tissue during the necropsy. That's why, as a city, we are really intentional about integrated pest management, which is identifying, monitoring populations, and dealing with prevention. Those front of the equation, removing food, removing harborage, educating the public so they can be a part of the ongoing work to solve, and then prioritizing non-rodenticide control. That's carbon dioxide, carbon monoxide.

The pilot right now with rat contraceptive, we'll see what the outcomes of that are, because what we know is extermination cannot solve this issue. These animals have too great a fecundity. They can breathe at just such a remarkable rate that extermination does not control the population long term. What we want New Yorkers to do first and foremost, check out nyc.gov/rats, check out the Department of Health Rap portal to see property-level inspections. See what's going on in your block, your neighborhood, your local park, report issues to 311.

That's how we direct resources like health inspectors or city staff to areas of concern, and take a look at the New York City rat pack, nyc.gov/service. Search rat pack, and you can get trained up on everything rat in New York City and get a T-shirt and hat and really be a part of the solution.

Brian Lehrer: Kathleen Corradi, Citywide Director of Rodent Mitigation for New York City, otherwise known as the rats czar. Thank you so much for joining us today and answering listeners' questions.

Kathleen Corradi: Thanks so much, Brian.

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