- There are ways to mitigate small roach invasions, but infestations should be handled by exterminators.
- Close up any openings to a home and maintain a vegetation-free zone to keep roaches out.
- Avoid foggers and instead kill roaches with diatomaceous earth, boric acid, or gel-based baits.
You probably know the feeling — the stomach-dropping moment when you hear a faint scuffle on your floor and look up to see a large, dark roach scuttling across your room or kitchen. No bug infestation is a particularly fun experience, but roaches somehow take things to a whole new level.
Scot Hodges, vice president of technical services for Arrow Exterminators, says cockroaches fall into two categories: domestic or peridomestic.
- Peridomestic roaches live in our surroundings but will typically migrate indoors once the weather gets colder.
- Domestic roaches, on the other hand, tend to coexist with humans in homes all the time.
Because of this difference, Hodges likes to classify the arrival of peridomestic roaches as either an infestation or invasion.
- An invasion is when roaches have only just sought refuge in a house, like when you open your garage door and see a roach scuttle across the concrete. Invasions are easier to manage by identifying how and why they arrived in the first place, then closing up entry points to a house and eliminating the few that have already entered.
- An infestation, however, is when the roaches are living and completing their entire life cycles in a house. "Once they move in, they do not move back out. You either have to kill them, or live with them," Hodges says.
How to identify types of roaches
Hodges says being able to identify different roach species, as well as if they're domestic or peridomestic, will help you understand how and why roaches might be entering your house in the first place and which methods to try first.
- German cockroaches (Domestic): One of the easier cockroach types to identify according to Hodges, German cockroaches are a tannish color and have two parallel dark stripes, also known as rally stripes, that run from their heads down their backs. And if getting close enough to catch a glimpse isn't a possibility, Hodges says there's another way to tell if a home has German cockroaches: the smell, which Hodges likens to a diaper pail. Given German roaches are domestic and already live indoors, Hodges advises focusing on mitigating their presence by eliminating food, water, and harborage in rooms like the bathroom and kitchen.
- Brown-banded cockroaches (Domestic): Similar to German cockroaches, brown-banded roaches also have two light brown stripes. However the stripes on a brown-banded roach go across their abdomen. These roaches like to occupy warm areas of a house, meaning you'll typically find them in high places.
- Smokybrown roaches (Peridomestic): The bodies of these roaches, which are mostly a deep, dark mahogany with an almost black pronotum, which is the shiny shield-like covering on a roach's head, can get very large, sometimes 1 ½ to 1 ¾ inches. They can fly very well and typically enter a home via the surrounding vegetation. Because of this, Hodges recommends practicing good exterior maintenance and treatment to help control Smokybrown roaches from migrating indoors.
- American cockroaches (Peridomestic): Like the smokybrown roaches, American cockroaches are large, can move through the air, and tend to get into houses through vegetation. However American cockroaches glide more than fly through the air, and are even bigger than smokybrown roaches, typically growing up to 1 ¾ to 2 inches. Hodges says one of their other more notable features is that their heads look a bit like a raccoon mask, with a mostly gold head and little darker brown spots.
- Oriental cockroaches (Peridomestic): While it's pretty standard to see cockroaches scuttling across your floor, Oriental cockroaches likely won't move like that given they're not very agile. They're black and don't have the ability to climb straight up a wall, leading them to mostly infest in ground-level areas like sewage.
How to get rid of roaches
Hodges says there's no singular silver bullet approach that will completely eliminate roaches from a house, but rather a combination of many to help deal with the problem. These methods help mitigate small invasions. An exterminator should be called in the event there's a larger issue.
Exclude roaches from your home
The first line of defense when combating roaches is to "use the pest's biology to outsmart it," according to Amy Cross, the project coordinator at the National Pesticide Information Center. In other words: eliminate any causes for why they might be entering the house.
Here are a few important roach resources to secure:
Food: Roaches need food to survive, and if it's available in your home, they'll try to stick around. Wipe or vacuum up any crumbs on floors, tables, and counters. Don't leave food unsealed in your pantry. To ensure it's out of reach of pests, store open pantry foods in airtight containers. Roaches also eat substances we don't consider food, such as hair, soap, and toothpaste. Try to keep your home clean and store away any potential items that roaches may try to feast on.
Leaks: Water is another resource that supports roach life inside of your home. If you have any leaky pipes or areas where water pools or drips, such as underneath sinks or in basements, roaches are likely to congregate there. To drive away roaches, fix any leaky pipes and replace leaky faucets. Repair any other places where outside water can enter your home, such as a leaky window or roof. If your basement is moist, try using a dehumidifer or sump pump.
Hiding spots: During the day, cockroaches often hide in dark areas. Stacks of cardboard boxes, newspaper, and other clutter can make perfect hiding spots for roaches. Break down the boxes and recycle them instead of harboring a potential roach hideout in your home.
Points of entry: Close up points as many points of entry as possible. This could include affixing a door sweep to cover the crack between the bottom of a door and the ground, or sealing up any holes in the foundation of a house.
Outdoor foliage: Hodges also says to maintain clean gutters, and to keep a vegetation-free zone with your landscaping by eliminating any foliage hanging over a house and not adding mulch when it's not necessary.
Collect and dispose of roaches with glue strips
Glue strips are one of the safest and most effective solutions for killing roaches, says Hodges.
Glue strips are sheets or tubes covered in a sticky substance and they can quickly catch cockroaches within 24 or 48 hours. While Hodges says these won't work for large infestations, they can help with monitoring the severity of a roach situation and indicate the severity of an issue.
Bait and kill with boric acid
Boric acid is a stomach poison that roaches don't have any resistance to. A roach must consume the boric acid for it to work.
However, it does come with a few caveats, as both Cross and Hodges point out. First off, Hodges explains it's a slow-acting agent and takes a while to actually kill roaches. On top of that, Hodges states people often panic and use more than necessary.
"The rule that we use when applying any type of a dust insecticide is that if you can see it, you've put out too much," Hodges says. "If the roach sees that big old pile [of boric acid], they're just going to walk around."
To attract roaches to the boric acid, mix it with equal parts sugar and water. Put the mixture in an open jar and place it where you've seen roaches. After roaches consume the mixture, they'll eventually die.
Hodges also encourages people to exercise caution, as boric acid can be toxic in large doses according to the National Pesticide Information Center, and to make sure they're following the instructions on the label when it comes to application.
Sprinkle some diatomaceous earth
Diatomaceous earth works as a scratching agent or abrasive meant to get spread out on a surface that insects will then run across. The diatomaceous earth will then damage or stick to the exoskeleton, causing them to dry out.
Similar to boric acid, this option is slow working and oftentimes is applied by people in overly large quantities or incorrectly.
According to Hodges, using too much can sometimes cause itchy or sore throats with homeowners, and Cross also points out that overapplication can render diatomaceous earth ineffective since the roaches will see it and just crawl around it.
Add baking soda to your arsenal
Baking soda is another common household substance that you can add to your pest-fighting arsenal.
Mix baking soda and sugar to bait the roaches. When they eat the baking soda and consume water, it will cause their insides to bloat and expand, which kills them.
However, baking soda alone is not as effective as boric acid. But you can combine them.
A 2013 study found that pellets made from a combination of three parts boric acid and one part baking soda were effective at killing roaches, with an average death time of 5 hours after ingestion.
Repel roaches with essential oils
Essential oils can be helpful if you're dealing with a few roaches entering your home from outdoors.
You can create a spray with at least 2.5% essential oil mixed with water, then spray it around areas where roaches might enter or where you've seen them.
Here are several essential oils proven to be effective against specific roach species.
- Citrus: A 2009 study found that a variety of citrus essential oils — including grapefruit, lemon, lime, and orange — were effective at repeling several species of roaches. This is likely due to limonene, a chemical in citrus peels that is also used in insect repellants.
- Kaffir lime: In a 2007 study, researchers found that kaffir lime oil was 100% effective at repelling both the American cockroach and German cockroach.
- Oregano: In a 2016 study focusing on the brown-banded cockroach, oregano oil was 96.5% to 99.1% effective at repelling the pest.
- Rosemary: In the same 2016 study, researches found that rosemary essential oil was toxic to brown-banded cockroaches, with 100% mortality after 24 hours of exposure to the oil at a concentration of at least 2.5%.
Try an insect growth regulator
If you have domestic roaches, such as the German cockroach, or if you think roaches are reproducing in your home, purchase an insect growth regulator product, such as a spray formulated with Pyriproxifen. These products focus on roaches at the egg and nymph stage, often rendering them unable to reproduce or mature into adults, and thus reducing the population.
Insect growth regulators are best used in tandem with products that kill adult roaches, since they often do not work on fully grown roaches and can take several months to have any noticeable effect.
Use a syringe to apply gel baits
Products that bait roaches with a gel applied via syringe make it easier to cover a wider variety of hard-to-reach areas. Covering more surfaces also makes it more likely that roaches will come across the bait.
Experts recommend applying small dots of the gel in areas where roaches may forage or enter and leave, such as in corners, under cabinets, and near cracks and edges. It's better to use small dots in many areas, rather than large globs in just a few areas.
Baits can take one to three days to kill roaches, allowing them time to potentially infect other roaches, as well.
Step on it
When you see a roach, step on it. That's one less roach you need to worry about in your home.
After stepping on a roach, disinfect the area with antibacterial cleaner to avoid spreading any pathogens the roach may have been carrying.
Pull out the poison and traps
Sometimes you have to pull out the big guns. Roach poison and roach traps are easy to come by and sometimes instantly effective. Here are some of our top recommendations for killing roaches:
While it's better to leave large roach infestations to the professionals, there are certainly mitigation techniques that can be used to eliminate roaches and keep them from returning to a home.
Closing up cracks in a house and getting rid of anything that might be attracting roaches in the first place is the best line of defense, and glue strips are also a highly recommended option when it comes to efficiently catching roaches.
You can also try natural methods such as diatomaceous earth or essential oil sprays. But if you continue to see roaches in your home, you might need to invest in chemical methods such as syringe-applied gel baits, insect growth regulators, or roach-killing sprays.
Home & Kitchen Reference Fellow
Megan was previously a fellow for the Home & Kitchen Reference team. She is based in New York, and has also worked as an assistant producer at WUGA-FM as well as a content editor for The Oultaw Ocean Project. She also interned with HGTV Magazine in 2019 through the American Society of Magazine Editors summer intern program. She graduated from the University of Georgia.