How To Kill A Cockroach

Written by Brandi Allred
Published: February 4, 2022
Image Credit pixfly/Shutterstock.com
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Out of nearly 5,000 species of cockroaches around the world, only around 30 are considered harmful to humans. These few species, unfortunately, give all roaches a bad reputation, and leave people wondering: how do you kill a cockroach?

Luckily for home and business owners, there are many ways to kill roaches—some of them easier and less toxic than others. Cockroaches love many of the same things we love; food, water, warmth, and a nice place to live. This shared love often brings them into our homes, where, unfortunately, they are often the cause of ill effects in humans and pets. Roaches carry disease and pathogens, and their feces and shed skins can cause asthma, or even cockroach allergies, in people.

Here, we’ll learn how to kill a cockroach, starting with learning how to determine if the bug you’re looking at is a roach at all. We’ll explore the signs of a cockroach infestation, then take a look at five ways to get rid of these unwelcome intruders. Finally, we’ll cover each method in detail, and analyze just how dangerous each might be to you and your pets.

Is It a Cockroach?

Cockroaches are notorious for scurrying around in the dark, and scattering as soon as the lights come on. But, in order to kill a cockroach, you have to know it’s a roach first. 

Cockroaches are medium-sized insects; most household pest species are between ¼ inch and 2 inches long. Their antennae are longer than their body, and they have six spiked legs used for climbing and running away. They range from red-brown to brown-black in color; young roaches (nymphs) are translucent white to pale brown until they reach adulthood. Beetles, water bugs, termites, and bed bugs are all species commonly confused with cockroaches. 

Signs of a Roach Infestation

Often, the first sign you’re going to need to kill a cockroach is the sight of a single cockroach. One roach is almost never just one roach; if you see one, there are more that you can’t see. Other signs of a potential infestation include baby cockroaches, shed exoskeletons, roach feces, dead cockroaches, stains, and foul smells.

5 Ways to Kill Cockroaches

American cockroach on wood
Boric acid, bait traps, baking soda, and insecticides can all be used to kill a cockroach

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The good news for homeowners dealing with a roach infestation is that there are many ways to kill a cockroach. These range from taking care of the problem entirely on your own to hiring a professional pest exterminator. Let’s take a look at five of the best methods for killing roaches in your home or business.

1. Boric acid 

Does Boric Acid Kill Cockroaches - Boric Acid
Boric acid is a popular way to kill cockroaches and often comes in powder form.

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One of the most popular methods for killing cockroaches and dealing with infestations is the application of boric acid. Boric acid is harmful to humans and pets when ingested, so use extreme caution to limit exposure, and don’t place it anywhere pets or children might find it. 

Boric acid usually comes in powder form. The powder should be sprinkled in areas where cockroaches frequent. When the roaches walk through the boric acid, it sticks to their bodies. Later, when the cockroach grooms, it ingests the boric acid, and quickly dies.

2. Baking Soda

Boric Acid And Cockroaches - Natural Pest Control Methods
Cockroaches will eat baking soda when it’s mixed with sugar. Ingesting baking soda is quickly fatal.

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Another way to kill a cockroach is by getting them to eat baking soda. Roaches won’t just eat any baking soda you put out for them though, it has to be mixed with something they like, like sugar. They don’t like baking soda on its own, but the sweet scent and taste of sugar masks the bad taste and smell of baking soda.

The baking soda, though not harmful on the outside, becomes deadly once the roach ingests it. It interferes with the cockroach’s internal systems and leads to a quick death. The best thing about using baking soda is that, unless it’s consumed in vast quantities, it’s not harmful to children or pets who might accidentally find it.

3. Bait Traps

One of the most effective ways to kill a cockroach is to use a premade, roach-specific, bait trap. These traps often have entryways with bait in the middle. The cockroach enters, but can’t escape. Other types are filled with liquid bait that attracts the roach. The roach feeds on the bait, then dies later. Often, the cockroaches bring traces of the bait back to the nest, further spreading the impact of the bait trap.

Bait traps should be placed in areas that cockroaches frequent, like the base of a wall, or beneath furniture. A good rule of thumb is, if you’ve seen a roach in that spot, it’s probably a good place for a trap.

4. Insecticides

You can kill a cockroach using diatomaceous earth or baking soda

gan chaonan/Shutterstock.com

Sprayable insecticides are a widely available and easy-to-use method when it comes to killing a cockroach. You can either spray the roach directly with the spray to kill it, or spray the insecticide on a surface. If you have a cockroach problem, spraying insecticides in areas frequented by roaches, like cracks, pipes, the bases of walls, and beneath cabinets, is a good idea.

You can also use insecticide spray as a roach deterrent, and many people do exactly this at regular intervals. If you hire a professional pest exterminator, they will likely use some kind of sprayable insecticide.

5. Diatomaceous Earth

The final method to kill a cockroach is to use diatomaceous earth. Diatomaceous earth is made of ancient fossils; these fossils are broken up into small, sharp pieces. It’s not meant to be eaten by the roaches, instead, it’s meant to kill them from the outside.

When a cockroach walks through diatomaceous earth, the earth actually destroys the waxy coating that covers the roach’s exoskeleton. This leads to rapid dehydration and death. Better yet; cockroaches often track diatomaceous earth back to their nests, where it gets on other roaches.

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About the Author

Brandi is a professional writer by day and a fiction writer by night. Her nonfiction work focuses on animals, nature, and conservation. She holds degrees in English and Anthropology, and spends her free time writing horror, scifi, and fantasy stories.

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