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Give Pests the Cold Shoulder This Winter

Ways to make sure your properties don’t attract any occupants but humans this season.

By Hope Bowman

Food stored in non-airtight containers can attract rodents, including rats, especially those in search of a warm home in winter.

As temperatures drop, your residents will be looking to keep their spaces cozy and warm, and they probably aren’t thinking about how to keep pests out of their homes. But a variety of common pests will be looking to escape the cold just like the rest of us, in a process called “overwintering.”

Apartment buildings have an ample supply of food and hiding spots, which makes them the perfect target for overwintering pests. Insects can overwinter at any stage of development, from larva to adults, and their hibernation habits differ by species. Some actively feed and grow during the colder months, some breed, and others just lay low until the temperature rises again in the spring.

In any case, you almost certainly can expect a number of common pests to try to take up residence on your property as the weather changes, but a few important strategies can help you keep the heat in and the intruders out.

Let’s start with a look at a few of the most common cold-weather pests.

Rodents: A Serious Health Threat

Rodents are perhaps the most troubling of the pests that can infiltrate multifamily dwellings. More than just a nuisance, rats and mice are a serious health threat. According to the Centers for Disease Control and Prevention, rodents can spread more than 35 diseases, some of which can be deadly. It doesn’t take an actual rodent bite for these diseases to spread to humans. Contact with food or surfaces contaminated by rodent feces, urine, or saliva, or simply contact with the pest itself, can be enough to transfer disease.

Beyond being a health concern, rodents also pose a safety hazard. They love to chew and often cause serious structural damage by gnawing on everything from wood and drywall to electrical wiring. The damage often happens completely out of sight, and by the time it’s discovered, the repair work needed can be expensive.

Unfortunately, rats and mice can be tricky to keep out. These nimble pests can compress their skeletons to squeeze through surprisingly small openings: A full-grown rat can fit through a hole the size of a quarter; a mouse, a hole the size of a dime. Once they get in, they can reproduce quickly, leading to an infestation behind walls, in crawlspaces and attic areas, or under the floorboards.

Some signs to look for that could indicate you have a rodent infestation:

1. Droppings: Rodent droppings can be found pretty much anywhere rodents go. Mouse droppings are about the size of a grain of rice; rat droppings, the size of a raisin. Both look like tiny pellets.

2. Urine trails: Rodents leave behind urine trails to communicate with one another. You may notice a distinct odor coming from areas of high rodent traffic.

3. Gnaw marks: Gnaw marks often can be found around corners and along baseboards where rodents travel most frequently. Residents may also find damaged food products.

4. Grease and rub marks: Look for yellow and brown discoloration along baseboards, another sign of rodent activity.

Seasonal Invaders

Depending on where it’s located, your building can be prone to a variety of pests that come and go with the seasons. Some of these, like Asian lady beetles, stink bugs, and cluster flies, don’t necessarily pose the same health and safety threats rodents do, but they’re a nuisance nonetheless. And they certainly will look for a warm place to overwinter as the temperature drops.

Asian lady beetles, commonly known as ladybugs, will gather in large numbers on the outside of light-colored buildings, often looking for the warmth of sunlight. As they gather, they find cracks, crevices, and holes to sneak inside.

Stink bugs also look to bask in the warm sunlight in colder months and can be found on walls of buildings where the sun hits. Stink bugs are not dangerous, but if they feel threatened, they’ll live up to their name.

Likewise, cluster flies can be found on the sunniest sides of a building. Slightly larger and darker than the common housefly, cluster flies can crawl through small openings around screens, doors, vents, and walls in search of an overwintering home in wall voids or enclosed ceiling areas.

Bigger Pest, Bigger Problem

When thinking about pest prevention, we tend to focus on the most common intruders, like insects and mice, but winter pests don’t always come in small packages. As the pest gets bigger, so do the potential problems.

Birds, raccoons, and squirrels can quickly cause a lot of damage in multifamily properties. Birds can carry numerous diseases, and their droppings corrode metal and deface outdoor walls. Squirrels love to seek shelter in roofs or attics, and once inside, they can cause an amazing amount of damage in a short amount of time. Raccoons are quite clever, able to open doors and latches. An uncapped chimney is a welcoming invitation to these nocturnal marauders.

It’s Cold Out There

Now that you know some of the most common pest threats during cold months, here are a few tips to keep them out of your buildings:

1. Mind the gaps. Inspect the interior and exterior of your building for holes or gaps. Inside, look behind furniture and in the corners and cabinets for any potential pest entryways. Seal any openings, gaps, or cracks with caulk or protective sealant to ensure a strong line of defense against pests that may be searching for a comfortable place to overwinter. Install tight-fitting door sweeps and weather stripping on doors and windows to close any gaps large enough for rodents or insects to squeeze through.

2. Take out the trash. Keep Dumpsters or trash cans as far away from your building as practical. Make sure they have lids, and have them cleaned regularly. Also make sure your community has routine garbage pickup so you avoid overflowing bins, which are an open buffet to many pests.

3. Don’t forget wood and leaf piles. If you keep wood or leaf piles on your property, be sure to maintain at least 20 feet between the piles and any buildings. These piles are warm, moist havens for pests, and the closer to your buildings they sit, the more likely you are to experience a pest problem.

4. Watch out for moisture. Check for leaks, specifically in bathrooms, attics, and basements. Water is as essential to life for pests as it is for humans. Moisture accumulation will attract a variety of pests and can damage property too.

5. Keep it clean. Don’t leave any food out in common areas. It sounds so simple, but it’s one of the most common reasons for pest problems. Crumbs and food stored in non-airtight containers can attract rodents from afar with promises of an easy meal. It’s important to keep common-area refrigerators and dishwashers clean as well. Odors alone can be a signal for pests to come dine.

Look at it from the pest’s point of view—wouldn’t you do anything you could to get inside a nice, warm space when it gets cold outside? You would, and so will they. So, keep these tips in mind and, in general, think like a pest. It’ll help you spot the signs of their presence and determine ways to keep the invaders out. When in doubt, call a pest-control professional for advice.

Hope Bowman is a technical specialist and board-certified entomologist with Western Pest Services, a Parsippany-Troy Hills, N.J.–based pest management company serving businesses and homeowners in major Northeastern markets.

Originally featured at Multifamily Executive.