To an entomologist, cockroaches are wonders of nature. But to a homeowner, they're just pests. Here's how to get rid of them and keep them away.
Homeowner’s Guide to Cockroach Pest Control
Cockroaches deserve a certain amount of respect. Scientists believe they originated in the Carboniferous Era about 260 million years ago, and speculate they’ll still be around after most other life forms on this planet vanish.
They’re incredibly strong, supporting 900 times their body weight. They can stay underwater for up to 40 minutes, survive temperatures down to 32 degrees and live for a week without a head. That’s right … without a head! They run at three miles mph (really fast for their size) and can squeeze through extremely tight spaces.
Fascinating as these qualities are, they make cockroaches extremely difficult to control. And because these oily-to-the-touch pests carry bacteria that cause diseases like dysentery, cholera and typhoid fever, they need to be controlled.
Compared to other insects, cockroaches are giants. That makes an infestation hard to overlook, especially when roaches are scurrying around inside your pantry or across the floor.
Because cockroaches have been around so long, they have likely invaded every type of human shelter imaginable. The best strategy for keeping them away hasn’t changed much through the ages: Deny them food and water by keeping your house clean. For people living in modern multi-story houses, exclusion techniques and additional control methods are typically also necessary.
Many commercial products are available for cockroach control, and you can make your own from simple household ingredients. But cockroaches are smart and adept at evasion, so sometimes calling in the pros is your best strategy.
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What Are Cockroaches?
It’s rare to find someone who has never seen a cockroach. If you’ve been that lucky, they’re six-legged insects from one-half to two inches long. (The largest recorded was six inches.) Their flat, oval-shaped bodies feature two long antennae. Many have wings, and some can fly.
Planet Earth hosts some 3,500 to 4,000 species of cockroaches, but only 30 of them are considered pests. If you live in North America and have an infestation, it’s probably one of these:
- American cockroach (Periplaneta americana): Shiny reddish brown, about 1-1/2- to two inches long, this species has wings longer than its body and loves fermented foods. It’s the one most likely to be in your pantry.
- Brown-banded cockroach (Supella longipalpa): Light to medium brown and about 1/2-in., this species has brown bands on its wings. It prefers warm climates and will live inside buildings.
- German cockroach (Blattella germanica): The most common species in the U.S., it’s light brown to tan and about 1/2-in. long. It has wings but rarely flies.
- Oriental cockroach (Blatta orientalis): Dark brown to black, this species grows to about one inch long. It likes things cool, so it’s most often found in basements.
- Smokybrown cockroach (Periplaneta fuliginosa): Ranging from 1 to 1-1/2 inches long, this shiny brown species prefers to live outdoors. If a cockroach buzzes around your head at night, it’s probably this one.
- Australian cockroach (Periplaneta australasiae): About 1-1/4- to 1-1/2-in. long with wings, this species loves water. It tends to inhabit drains and open sewers.
What Attracts Cockroaches to Your Home?
Food, water and warmth. You could have an infestation even if you clean meticulously, because they sometimes find what they need in dark corners where you rarely go.
Here are some specific things that attract them:
- Dirty dishes in the sink;
- Overfilled trash cans;
- Plumbing leaks (water and sewer).
- Crumbs on shelves, countertops or the floor;
- High humidity and condensation in the kitchen, laundry room or bathroom.
Sometimes cockroaches enter a house on their own, but sometimes they hitch a ride on parcels and boxes. People have found German cockroaches hiding in cases of soda they just purchased!
Signs of a Cockroach Infestation
Of course, the sight of a cockroach scurrying across the floor or running for cover when you open a drawer is a pretty good sign of an infestation. But cockroaches are adept at hiding, so there’s a good chance you won’t spot any.
Here are some other signs you have a cockroach problem:
- Droppings: These can look like pepper or grains of sand. You might see them in sink cabinets or other dark, moist places.
- Odors: Some species emit musty, oily or even sweet odors. The bigger the population, the stronger the odor.
- Shed skin: Cockroaches shed five to eight times as they grow into adults.
- Tracks: In moist areas, cockroaches leave smear marks on horizontal surfaces.
- Egg capsules: Female cockroaches lay capsules that contain up to 40 individual eggs. Each capsule is about half the diameter of a penny and may be brown or black, depending on the species.
How To Get Rid of Cockroaches
Once you’ve got a cockroach infestation, here are your options for treating them: Baiting, trapping, applying chemicals or deploying deterrents to make them go away.
Baiting is one of the most popular and effective control methods. You can buy commercial bait or make your own. Mix flour and sugar with about 5% boric acid, add a little water, then roll the mixture into balls placed near areas of activity.
Sticky traps are also effective. But if you have a large infestation, they’re best used to identify areas of activity so you can place bait there.
Pros and cons of DIY extermination
DIY cockroach extermination saves money (about $250 to $350 on average) and gives you control over which chemicals are used in your home. The downside is, you may only kill the cockroaches you see, and fail to address the larger colony hiding in the walls.
Doing it yourself is more convenient, though, because you don’t have to coordinate schedules with anyone.
Pros and cons of professional extermination
Of course, hiring an exterminator costs more, but it usually comes with a guarantee the problem will be solved. Professional exterminators know more about cockroach habits than homeowners, and they are more likely to eradicate an infestation — even a large one — the first time around.
How To Prevent Cockroaches From Coming Back
A clean, dry house, together with sealing all openings cockroaches can squeeze through, is the best way to keep them away. Dusting areas of activity with diatomaceous earth will prevent them from congregating because DE lacerates their legs and exoskeletons.
You can also spray areas where you’ve seen them with essential oils they don’t like, like peppermint, tea tree, cedar and cypress.
If you’ve seen them emerging from the baseboards, spray boric acid behind the wall. It’s a poison that can kill them as they groom themselves. Boric acid is slightly toxic, so don’t leave it anywhere pets or children can come in contact with it.
And be warned: Dead cockroaches you can’t reach with a vacuum will give off a strong, musty odor as their decomposing bodies release oleic acid.