The list of pests that can invade your home is long. Spiders, silverfish, termites, ticks, stink bugs, crickets—pretty much anything that lives outdoors can make itself at home indoors. But the following are five of the most common, at least in the United States. Here’s a guide to your unwanted housemates … and how to get rid of them.
Ants
They’re notorious for ruining picnics, but they also have the ability to invade your home. Ants carry bacteria and might transfer them to food or an open wound. Various disease-causing organisms—including E. coli, Streptococcus, Shigella, Salmonella, and Staphylococcus—have been found on some species of ants, especially in developing countries.
But “most common species in the United States generally do not cause public health hazards,” according to the Environmental Protection Agency (EPA). There’s no evidence that ants spreading disease is a significant risk, and ant-related illnesses have not been reported. Ants have pincer-like jaws and the ability to bite—though they rarely do. (Fire ants sting, but they almost always stay outdoors.)
Regardless of health issues, who wants lots of ants crawling on their food and furnishings? Start by making your home less hospitable to ants. Store food in tight containers. Clean up soiled dishware and food crumbs—ants may not be lured in by bait traps if other sources of food are around. Remove sources of moisture as well.
Follow ants to their entry points, and seal cracks and crevices. Wipe up invading ants with soapy water to erase their odor trails. Ant baits are more effective than sprays, as they allow ants to live long enough to take the poison back to the nest with them—where they spread the poison to other ants. Traps are available in hardware and grocery stores.
If these measures don’t suffice, you can apply boric acid dust (wearing a dust mask) or diatomaceous earth (silicon dioxide) at entry points, making sure to keep these substances out of the reach of children and pets. Boric acid is ingested by the ants, and it works by destroying their nervous and digestive systems, as well as their exoskeletons; diatomaceous earth damages their exoskeletons, causing the ants to dehydrate and die.
Bedbugs
Although infestation rates declined during the Covid-19 pandemic (due to people staying home), as travel returned, so too did bedbugs.
Thankfully, they aren’t known to transmit or spread disease, but they can cause other health problems. They can and do bite, which can result in itchy red sores. If you scratch these bites, they can become infected. It’s rare, but the bites could cause allergic reactions, including hives and wheezing. Bedbugs can affect your mental health as well, often leading to anxiety, insomnia, nightmares, hypervigilance, and even delusions of being infested with parasites.
Bites may be the first sign that you have a bedbug problem, but there are other signs (and not everyone has a visible reaction to bites). You may see rust-colored or reddish stains on bedding or mattresses, the result of bedbugs being crushed. Dark spots (about the size of an asterisk printed in a book or magazine) are bedbug excrement. You might find whitish to pale yellow eggs and eggshells about 1 millimeter in size. And of course, you could see an actual bedbug—about the size of an apple seed, with a flat, oval-shaped brown or reddish-brown body.
When feeding, bedbugs are attracted to your body heat and the carbon dioxide you exhale. During non-feeding times, they can hide (and lay eggs) in a variety of places: near the piping on a mattress, in cracks on a bed frame or headboard, in couch cushions and curtains, in electrical outlets and appliances, and under wallpaper and wall hangings.
While many other pests can be eradicated on your own, bedbugs are one type where hiring a professional is a good idea. Call as soon as you spot any signs, and hire someone with bedbug experience. Follow instructions on laundering and cleaning precisely, and don’t be surprised if full eradication requires several treatments and is expensive.
To help avoid bringing bedbugs home from your travels, pack in a hard-sided suitcase—bugs prefer to adhere to soft material. Pack your clothing in resealable plastic bags, and keep them in there for the remainder of your stay at a hotel or other accommodation. To check for bedbugs, use a flashlight (even the one on your phone) to inspect the room—mattress, box spring, headboard, pillows, upholstered furniture, and drawers—before you even open your suitcase. If you see any signs of bedbugs, tell the hotel or property manager and request another room or accommodation.
Cockroaches
These flat, oval-shaped insects have six legs that let them quickly scurry across your kitchen floor when you turn on the lights. Four of the most common types are German (pale brown), American (large and brown or reddish-brown with wings), Oriental (glossy, dark-brown or black bodies), and brown-banded (two light yellow bands across their bodies).
Cockroaches often scavenge for food at night and hide in crevices, including behind stoves and refrigerators. They’re common all over the world. According to the American Housing Survey, conducted as part of the U.S. Census, 14 million (out of 124 million) households reported seeing roaches in their homes in the previous 12 months. While cockroaches don’t bite, their droppings and the “skin” (exoskeleton) they shed can cause or worsen allergic conditions.
Having cockroaches doesn’t mean your home is unclean. These insects are experts at finding small holes and cracks and searching out even minuscule traces of food and water. Certain factors do make it more likely that cockroaches will enter your home, however, including broken windows and cracked interior walls. Cockroaches can also raid apartments via plumbing or from neighboring units. To make your home unwelcoming to cockroaches, make sure all food—including pet food—is in sealed containers. Be sure that all cooking surfaces, countertops, and floors are free of food and grease. Repair any cracks or holes near doors and windows.
If you see a live roach, spraying it directly with a roach killer will take care of that one (but not the larger problem). If you spot eggs, droppings, or shedded skins inside your home, you can try treating with boric acid or diatomaceous earth (the same used to kill ants). Roach baits and bait stations can be effective and provide ongoing control. You can also try roach motels (“Roaches check in, but don’t check out”), but they only trap individual roaches and don’t address the root cause of the problem. If roaches persist, it’s time to call an exterminator.
Flies
Houseflies and blowflies, also known as common green bottle flies, may carry more than 200 different disease-causing microorganisms. That’s because flies feed and lay their eggs in feces, rotting flesh, and other decaying substances, where they come into contact with these pathogens. Flies are also known to feed by regurgitating enzymes from their bodies onto food. The enzymes break down the food into a liquid that the fly slurps up. As a result, any pathogens inside the fly can end up on your food.
But there’s no hard evidence that flies transmit pathogens through food that people consume. The risk of infection from microbes on food that are transmitted by one fly is low—although if a swarm of flies is crawling on your food, you certainly shouldn’t eat it. And, if you’re immunocompromised for any reason, you might want to err on the side of caution and pass on any food that flies have landed on, especially if the insects have been hanging out there for a while.
To get rid of flies in your home, fly bait, commercial traps, and insecticides are all good options. You can also make your own all-natural trap, although results may vary. Try pouring sugar water or a mixture of apple cider vinegar and fruit-scented dish soap into a bowl or jar. Cover tightly with plastic wrap, and poke a few holes in it. The flies will be attracted to the sweetness and get trapped under the plastic wrap. To keep flies out of your home in the first place, make sure your trash cans have tight-fitting lids and your window screens are free of holes or gaps. Applying insecticide sprays around the perimeter of your home can be beneficial, especially if applied in early fall.
Moths
These pests can affect your home mainly in two different places: your closet and your pantry. Clothes moths can’t harm you, but they will consume fabrics such as fur, wool, and silk. Two types—webbing and casemaking clothes moths—chew small holes in clothing and leave behind droppings and eggs. If you see these holes, check all closets and storage chests, then dry clean or wash and dry any infested clothing; you can also freeze the clothes (seal them in heavy-duty freezer bags) as another way to kill moth eggs and larvae—but it takes some time (at least 72 hours) and may not always work. Vacuum often to pick up any eggs or larvae.
Pantry moths—as the name suggests—like to set up camp where you store your dry food. They’re also called Indian meal moths. Although they can’t bite and don’t spread disease, they can be an expensive household pest, as you’ll end up throwing out the food that they’ve contaminated. Grains and processed products are common moth environments, and often these products came into your home already infested with moth eggs. Once they hatch, the larvae eat grains, nuts, cereals, and many processed products. The larvae then leave behind feces, cocoons, and web-like material that contaminate your food.
If you notice adult moths in your kitchen, check inside your stored food packages and in cracks and crevices in your pantry. Throw away any contaminated food to prevent the infestation from spreading. Vacuum inside your pantry regularly to avoid attracting more moths, and clean up spills immediately (especially flour and sugar, which are very attractive to moths). Store your dry goods inside sealed containers—these creatures can chew through plastic bags and thin cardboard.
While mothballs can be helpful in closets to kill clothes moths, they should never be used around food or in areas where food is prepared. The gases they emit can be harmful to people and pets.
BOTTOM LINE: Finding bugs in your home is never fun, but it’s not an indictment of your housekeeping. Even the cleanest homes can appear welcoming to these pests. The diligent storage and eradication practices described above can work wonders, but if they don’t, there’s no shame in calling in the pros. An exterminator is an essential first step for bedbugs, and you may need to make that call for difficult-to-treat cases of roaches, moths, ants, or flies as well. These services aren’t cheap—but better to have money going out the door than bugs coming in through it.
Got pests? Total release foggers (a.k.a. bug bombs) may not be the best solution. The toxic substances in foggers present acute and possible chronic health risks and have been linked to respiratory, gastrointestinal, neurological, dermatological, and other problems. The aerosolized particles are also highly flammable and can set off explosions—for instance, if pilot lights or gas fireplaces are on or if certain appliances are not unplugged.
And, as a study several years ago found, foggers weren’t as effective in combatting roaches as were gel baits, and they left insecticide residues on all horizontal surfaces for weeks after.
The EPA registers pesticides to ensure that they are safe to use, as long as you follow the directions on the label. But for serious problems, it may be safer and more effective to get advice from a pest control service. Some companies use integrated pest management, which minimizes the need for pesticides and other toxic chemicals.
