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How to Prevent and Fight Rodent Infestations

By Amy Zimmer | September 30, 2014 8:04pm | Updated on October 3, 2014 5:42pm
 It's essential to seal up holes like this one if you want to vermin out of your house.
It's essential to seal up holes like this one if you want to vermin out of your house.
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MANHATTAN — Shortly after Melissa Kinski moved into her Lower East Side tenement 20 years ago, she met her apartment's previous tenant, who said to her: "Be prepared for all the mice. They're going to be everywhere."

That first year on Ludlow Street, Kinski spotted two mice. One was under a bookshelf, already dead, apparently from bait. The other she shooed out after it finished eating a crumb.

Since then, she never let her guard down, said Kinski, a 44-year-old filmmaker. In the following two decades, she's had zero mice sightings.

She keeps all food (including cereal, dry pasta and crackers) in her refrigerator rather than cupboards. She seals cracks in the walls and floors as soon as she notices them. Just two weeks ago, she plugged some cracks with plaster and copper mesh (from scrub brushes she bought at Duane Reade). It was a method she learned from a building inspector.

"I do prevention," Kinski said.

Kinski has the right idea, pest control experts said. Tackling infestations involves dealing with structural and sanitary issues, they said, and the time to check your home is now. As the cool weather settles in, rodents begin to head indoors, looking for warm places to nest.

The neighborhoods with the most 311 rodent complaints in September included Bedford-Stuyvesant (65 calls), the Upper West Side (56 complaints),  Highbridge and Concourse (57 calls) and the areas covering Hollis, Jamaica and Springfield Gardens and Manhattan's Chinatown, Lower East Side and East Village (with 55 each), according to city data.

Here are some tips from the city's top environmentally-friendly pest control companies on how to fight or prevent infestations.

1. Look for the signs of rodent's presence

Mice don't generally live in apartments. They come in to explore and get food, and they'll continue to come and go as long as there are entry points, Thomas King, manager of M & M Pest Control said.

Telltale signs of mice, for instance, include "rub marks" on walls from their oily fur and droppings that are smaller than a grain of rice with pointy edges, he said. Rat droppings are about the length of a penny.

Rats tend to be more shy than mice and prefer hanging out around garbage in basements, but if they're "particularly hungry and desperate" — which can happen especially if construction disturbs their home — they'll find a way into someone's apartment, King added.

"If there is construction around, you are at greater risk," Arthur Katz, CEO of Knockout Pest Control said. "Digging and demolition disturb established populations that will head off looking for a new home."

It's helpful to be aware what attracts vermin. Infestations can be more common near schools and restaurants — where lots of trash bags are piled up with plenty of food for rodents — or near parks and subways.

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2. Look for ALL possible entry points and seal them.

Every crack needs to be patched to prevent an infestation.

"Rodents can squeeze through amazingly small spaces," said Katz. "If you can see light through a crack, a rodent can enter."

Look around doors and windows, around the foundation, and any place anything enters the building, like plumbing, electrical wires, phone, cable or gas.

3. Use the right materials to seal cracks

A lot of DIYers will use steel wool or caulk to seal cracks. But those are just stopgaps, experts said.

"Caulk is not enough," Katz said. "Rodents can chew through such materials. Cement and metal wire mesh are better sealants."

Steel wool can be moved by mice over time, especially if it's not compacted well, since wooden floors tend to move and swell in high humidity, King said.

"Use one material to anchor the other in place," King suggested. "We use steel mesh and sheet metal and plaster to anchor in place and to finish so it looks presentable."

4. Keep things clean in your building's basement and your home.

A building's garbage room should be proofed and kept clear of debris and clutter that can harbor rodents' nests, King said.

"If you control the numbers in the basement you should be able to control the numbers upstairs," he said.

It's also important to seal up access to food in your home and keep areas free of dirt and clutter, too, he added.

5. Traps and bait aren't that helpful.

Many buildings have monthly exterminators who will set traps or bait if you have vermin. But if entry points are not sealed, the rodents will return. Mice often live in families of up to 30 critters, King said.

Many chemicals used against rodents can be dangerous if improperly used, Katz added, noting the importance of using a professional to get rid of infestations and prevent future ones. 

"You might kill a few rodents that you can see, but the rest will survive and change their habits. Just because you don't see them does not mean they are not there," he said.

6. Don't count on cats.

Yes, a cat can be helpful, but it depends on the cat, Katz said.

"Some are natural hunters and some are scared of mice," he said.

Regardless, in a multi-unit building, even the most fearless feline can't do that much.

"A good cat is like a good trap," Katz said. "A good one can catch some rodents, but it won't wipe out an infestation and the problem will continue until entry points are sealed off."

7. First-floor units are more susceptible, but higher floors can have problems, too.

If cracks are sealed on the first floor, rodents will climb until they find a way in, Katz said.

"Rodents are athletic and determined," he said. "Just because you are one floor up doesn't mean you are safe."

King has seen major infestations on upper floor of high-rises, too.

"These are mice that have an established infestation in the building. They're living in floors and walls," he said. "They build colonies as they go up."

8. If you're buying a new apartment or renovating, call a pest control expert

House hunters should tour a building's basement to see how well maintained it is and if there are signs of rodent infestations, King advised.

For those planning any major apartment renovations, it also helps to call an expert to seal up gaps. 

"In a kitchen renovation, the ideal time is when the floor is finished and appliances are installed but before the cabinets are put on," King suggested to avoid bigger and costlier problems down the line if there's a problem that requires dismantling of cabinets.

"A lot of contractors will hide the holes with cabinets," he said. "They don't even realize it can be a problem."