What's Causing the Pest Problem in Your Home?

How your least favorite house guests get inside, and how to reduce the chances of an overwhelming infestation.

U.S. News & World Report

What's Causing the Pest Problem in Your Home?

(Getty Images)

When you find a bug on you, you're left all day with the unsettling feeling that something's still there. Even with constant swipes of the hand over your shoulders and arms to check, you can't shake the feeling that you've got another creepy crawly on you somewhere.

It’s even worse when it happens at home. Finding one ant can give you the eerie inkling that there may be an entire colony somewhere inside your home, just waiting to enact a hostile takeover of your house.

Unfortunately, there’s no way to completely eliminate the possibility of pests entering your home, whether you bring them in unintentionally or they find their own way inside.

“You’re going to have to deal with them your whole life,” says Jeff Whitworth, an extension specialist in entomology and associate professor of entomology at Kansas State University. “You can reduce the flow of pests into your house, but you’re not going to be able to keep them out entirely,” he adds. 

The first step to reducing the potential for pests in your home – whether they're insects, spiders or rodents – is to understand how and why they get there in the first place. Here are some of the most common ways and reasons pests get into your home:

They hitched a ride. As much as you may not want to admit it, you’re a leading culprit for bringing insects and spiders into your home. Typically, they’ll get onto a jacket, shoe or grocery bag, and then you carry them right into their new playground.

in the case of bedbugs, attaching themselves to a person, animal or object is the only way they spread from location to location, says John Kane, an urban and structural entomologist at the pest control company Orkin. “It’s just a case of bad luck. It has nothing to do with [a person’s] state of hygiene or the cleanliness of their home,” he says.

It probably doesn't happen often, and when it does it's typically only one or two pests entering your home at a time this way. But if they can find a consistent food source – and for bedbugs, that would be your blood – they’ll have offspring as quickly as possible, which causes obvious problems for you as the resident.

The weather drives them in. Seasonal change is a common factor bringing pests into homes, as they seek shelter from extreme weather conditions. “They’re our chief competitors for food and fiber. They’re very good at getting into areas that they can survive winter [and] heat in the summer,” Whitworth says.

It’s not just insects and spiders, either. Mouse and rat problems in homes are more common in fall, when the weather turns colder, and the rodents start looking for a warmer place to spend the winter.

Weather patterns and drought also play a big part in bringing outside creatures into the home, as pests seeking moisture will turn to buildings when there’s a lack of rain or moisture outside. In the San Francisco Bay Area, rat problems have increased as the California drought continues, explains Richard Estrada, president of ATCO Pest Control. Because the ground doesn't have much moisture, rats have had to turn to residences to find water, and while ridding a home of rats isn't necessarily more difficult because of the drought, it continues to be a growing problem in the area, Estrada says.

“Any time you see extreme changes in the environment, it upsets the whole ecosystem, and it affects the insect population and of course the rodent population,” Estrada says.

They’re claiming squatters’ rights. If you recently moved into your home and almost immediately started experiencing pest problems – beyond one or two hitchhikers from moving boxes – there’s a good chance they were there before you ever arrived.

It’s also possible that you were simply unaware of a problem before. For example, bedbug bites don’t leave the same irritation for everyone, so a new roommate discovering bite marks could mean they’ve been there all along without you having a skin reaction.

“When a bedbug bites – it pokes, really – its saliva has a painkiller, an anesthetic and anticoagulant, and ideally your body’s immune system would attack those foreign compounds, and you’d get an itchy red bump that would give you a warning signal that you’ve got a problem,” Kane says.

They like how you decorated. In addition to a food source, the way you keep your home could be providing the perfect habitat for certain pests to get comfortable, depending on their preferences, of course.

Brown recluse spiders, true to their name, prefer dark spaces away from a lot of activity. “They don’t like people, so they like something to hide in,” Whitworth says. “As long as you keep things picked up – you know, papers and boxes – you’re going to reduce their ability to cohabit with you.”

The same goes for outside your home, and near any potential entrances as well. Whitworth says it’s common in home gardens for people to put black plastic down and cover it with mulch or wood chips to control the growth of weeds.

“That makes an ideal location for certain pests, like termites, ants and pill bugs,” Whitworth says. To minimize the chances of those bugs getting into your home, he advises not putting the plastic against your home to keep the pests from congregating right at your foundation, which makes it all too tempting for them to try to get inside.

How Do You Minimize the Problem?

You have to be able enter and exit your home, so there’s no sure way to keep pests from coming inside your home. But a little diligence and a level head can help keep a few occasional sightings from becoming a full-on infestation.

Clean and close. General cleanliness and ensuring entrances to the home properly closed will be the biggest help in keeping out pests. Appropriately seal food packaging and clean up any crumbs so you’re not leaving a smorgasbord on the counter, and using caulk to close up any ant-sized holes near doors and windows will largely cut out the entrance method and reason for pests to enter your home.

Look out. For bedbugs in particular, Kane recommends checking around your bed and nightstand on a regular basis, and flipping your mattress can help you spot telltale signs of bedbugs (little maroon or black-looking spots) or even a bedbug itself. “Just walk around and take a close look at things,” Kane says.

Get sticky traps. To trap insects or spiders that may be lurking around, Whitworth recommends sticky traps – typically paper or cardboard with glue on the side facing up.

“It may not control them, but that will alert you to the fact that, ‘Oh, I’m catching a whole bunch of these little clothes moths on these traps. I may have an infestation of those coming from somewhere,’” Whitworth says.

Do the laundry. When you’re paranoid about bringing bugs in on your clothes, Kane says a tumble dry cycle could be the simplest solution. “A tumble dryer will cook any bug. Tumble dryers easily get in excess of 180 degrees Fahrenheit – that’s well above the needed lethal temperature,” he says. “That being said, never use the oven, never use the microwave.”

However, don’t let your paranoia get the best of you. Doing laundry every time you come in from outside is unnecessary, and it could leave you with prematurely faded clothing – and the need to buy new clothes sooner.

“I have known people who have slowly put themselves into financial difficulties from just constantly doing laundry. I would call that an overreaction,” Kane says.

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