New York State IPM Program

May 11, 2020
by Matt Frye
Comments Off on Rats in the time of Coronavirus Isolation

Rats in the time of Coronavirus Isolation

As an entomologist that specializes in pest management, the Coronavirus outbreak has resulted in some unique concerns. Recent attention has focused on how human isolation affects rodent populations, but other challenges await. Fear of food shortages led residents to stock up on items like flour, rice and pasta. With grocery store shelves restocked and a food shortage not realized, this hoarding behavior creates the perfect storm for pantry pest problems. Without proper storage in tightly sealed containers, these insects can infest forgotten items and result in ironic food waste, created by fear of a food shortage.

A group of rats eat spilled food from a plastic container during the daytime in an urban area.

Urban rats feeding on spilled food.

But for now, let us turn to the issue at hand – rats, and specifically urban rats. Across the country, as people retreated to their homes to isolate, once cryptic rats emerged to forage in broad daylight. Observers noted rats fighting over food, cannibalizing each other (muricide) and their offspring (infanticide), and moving to new locations. Sensational headlines talk of angry, mutant super rats, but what is really happening?

A rat standing on the edge of a metal garbage can with food in its mouth.

Rat feeding on food waste from a park garage can.

Let’s take a step back. Before humans were isolating, abundant food waste from restaurants, trash cans in parks, subways and housing areas provided nourishment to sustain large urban rat populations. Seemingly overnight, however, those predictable resources disappeared. The outcome is a struggle for survival and a thinning of the herd as large populations are challenged by limited resources. This is a case study on tenets of the Theory of Natural Selection, but is it enough to change the evolutionary trajectory of rats to create super rats? Definitely not. Modern rats are opportunistic animals that are already adapted to deal with food shortages. Movement to new areas and cannibalism are known rat behaviors, made obvious on a large scale during this pandemic. While it may feel longer, people have only been isolating for about two months in the US, enough time for one to two rat generations. Meanwhile, rat evolution has occurred over thousands of generations to create the “diabolically clever” animal we face today.

The truly important question we should ask ourselves is, how should we respond? The pandemic has provided an opportunity for people to see exactly how our behaviors and our management of food waste affects rodent populations. Indeed, we are the cause of our rodent problems. What steps can we take to manage rodent populations today and into the future?

To start, now is the ideal time for municipalities and pest professionals to work together to reduce rodent populations. Rats are stressed for food, making them more likely to feed on rodenticide baits and interact with baited traps. Efforts should be coordinated to the scale of the rodent population. For example, in New York City, data from the Rat Information Portal can guide management and direct adequate attention to areas with high rat pressure – rather than waste resources elsewhere. Furthermore, efforts must consider the management unit that will impact the rodent population. Whereas contracted pest management companies may service an individual store front or building, the rodent problem may span an entire block between nesting and feeding sites.

Now is also the time for building owners and managers to assess their facilities for pest entry points, and to use appropriate materials to seal openings. Not all materials are rodent-proof, and guidance on selecting the appropriate materials can be found on the Scientific Coalition on Pest Exclusion’s website. Keeping pests out of facilities is the best approach to minimizing exposure to rodent-borne disease and the physical damage that rodents cause by gnawing.Logo of the Scientific Coalition on Pest Exclusion. The letter O is made to look like a magnifying glass, with a silhouette of a rat inside the O. The bigger challenge is to devise long-term strategies that will reduce rodent access to food waste. If, upon lifting social distancing restrictions we return to “business as usual,” with trash bags left on street corners overnight, we will see a rapid return of rat populations and lose any ground we gained in the war on vermin. Certainly pest proof refuse containers would help, but not all solutions require an expense. Changes in the pickup schedule for food waste, the timing of when trash is placed on the street, how and where refuse is stored before disposal, and other considerations can be tweaked to minimize food availability for rats.

The Coronavirus pandemic will not create super rats, but can help us in the fight to reduce their populations and impacts – if we choose to do so.

graphic showing Dr Matt Frye

August 24, 2016
by Matt Frye
Comments Off on Fighting Waterbugs — with Water

Fighting Waterbugs — with Water

Plumbing issues lead to pest problems — there’s little doubt about that. Leaks offer standing water to rodents, and clogged, scummy drains are breeding sites for flies. How curious that one of the most common plumbing-related pest problems I see is drains and pipes without water.

Unused, uncapped drains are an open door for cockroaches and more.

Unused, uncapped drains are an open door for cockroaches and more.

Case Study
At a multi-story office building, workers reported the presence of waterbugs, aka American cockroaches, on unconnected floors. Sanitation at the site was great, and no obvious leak created harborage for cockroaches: both excellent IPM practices. But a thorough inspection uncovered an unused bathroom on one floor where the water had been shut off during renovation. Not only could we smell sewer gasses — this bathroom contained several dead American cockroaches, suggesting this was the source for that floor. On another floor a drainpipe in a mop closet was open, and we could see cockroach frass.

A drain trap — and never mind the large gap at the wall. Exclusion is an entirely different topic.

A drain trap — and never mind the large gap at the wall. Exclusion is a whole different matter.

Plumbing Traps 101
If you’ve ever looked under a  sink, you’re familiar with a plumbing trap: that U-shaped pipe that changes the flow of water from vertical to horizontal. Its job: to create a water seal that prevents odors and harmful sewer gasses from escaping into the living or work space. Each time the drain is used, fresh water replaces standing water in the trap to maintain a permanent seal.

Uncapped and unused.

Uncapped, unused — except as a highway for pests.

As side benefit, this design deters pests from using pipes to move within or between buildings. Sure, cockroaches and rodents (especially rats) can overcome plumbing traps by crawling through a small amount of water (see National Geographic video on rats in toilets). But when drains are regularly used, they’re unlikely to harbor pests.

Drain Fails
Problems with trap seals occur when drains are infrequently used and water evaporates over time, or if drains are clogged with debris. Floor drains are susceptible to drying out if

  • no one wet-mops the floors
  • they’re in production areas with lots of small spilled items or
  • they’re near a deep fryer
Water cannot penetrate drain grates clogged with dirt and debris. This drain should be cleaned (drain brush or shop vacuum) and flushed with water.

Water can’t penetrate clogged drains. Clean (drain brush or shop vacuum) and flush with water.

Inspection Tips and Solutions
Another core IPM practice: owners or facilities maintenance personnel need to check drains often to verify that water is present in the trap. Check them each time floors are cleaned. For traps that have dried out the solution is easy – pour water down the drain until the trap is full. While you’re at it, make sure that drains are clear of debris. If the pipe is cut and no longer used, cap the end for a permanent seal.

May 13, 2014
by Matt Frye
Comments Off on Top 5 Pest Hangouts — in Your Kitchen

Top 5 Pest Hangouts — in Your Kitchen

Spring! Time to fling open the windows, plant some flowers — and begin the annual tradition of spring-cleaning. But are you getting to all those places where pests find food, water, or shelter? Householders tend to overlook these five places. And they could be just the spots where pests come for a free meal or to catch a few zzzz’s.

Clean these often:

The Stove Top — or rather, the space right beneath it

Stove Top

Stove Top

Most cooks wipe down the top of the stove when they’ve fixed a meal. But what about the space under the stove lid? Here, spilled liquids, crumbs and other food materials can accumulate out of sight, providing food for rodents, cockroaches, and other pests.

Counter-Top Ledges

Counter-top Ledges

Counter-top Ledges

Crumbs, spilled coffee, whatever — they’re easy to see and clean up on your countertops. But food particles and liquid can accumulate on the undersides of ledges too. So while you’re at it, wipe down those ledge undersides.

The Toaster

Toaster

Toaster

Toasters and toaster ovens are great hidey-holes for crumbs. Lots of crumbs. Just be safe when you clean — unplug the toaster. Then pull out the tray and wash it. For even better results, invert the device to shake out the crumbs or go at it with your vacuum cleaner.

Behind the Faucet

Behind the Faucet

Behind the Faucet

The sink is our go-to place for cleaning dishes and utensils. But how often do we remember to clean behind the faucet or around its handles? Here, water and spilled food particles could make for the pest equivalent of the soup kitchen if not cleaned regularly.

The Trash Receptacle

Trash Receptacle

Trash Receptacle

Let’s face it — plastic bags are easy to tear. Too often, something we toss out tears the bag; then the combination of (for instance) food scraps and wet coffee ground means we’ve got stuff leaking out. The solution? Clean the receptacle when you take out the trash.

Sanitation. It’s core to managing pests.

All photos by Matt Frye, NYS IPM
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