How to Get Rid of Oriental Cockroaches

Oriental cockroaches or Blatta orientalis as they’re scientifically known are an invasive pest found in most parts of the world. They love damp, moist places and usually stick to building nests outdoors, but they have been known to infiltrate houses too.

They can spread diseases to humans and frequently contaminate food. Oriental cockroaches are also different in appearance from regular cockroaches—they are darker and resemble beetles.

Dealing with an oriental cockroach infestation can be very taxing. Most people don’t know what they’re dealing with and struggle to exterminate them completely. Here is the complete guide on how to get rid of oriental cockroaches:

What Are Oriental Cockroaches?

Oriental cockroaches are large insects that like to occupy damp areas in human dwellings. You are most likely to find them scurrying around in your kitchen, basement, or bathroom.

They can carry diseases like salmonella and are carriers of harmful pathogens, worms, and bacteria like E.coli. They usually prefer to live outdoors, but they can be found in damp, musty areas inside the house too.

If there is an oriental cockroach infestation in your garden or backyard, they have most probably invaded your home too. They can survive on almost anything but particularly enjoy eating rotten food from the garbage.

Oriental cockroaches are also called black beetles, water bugs or black cockroaches. They aren’t as fast as regular cockroaches. Their large size makes them move slowly, but this doesn’t mean they are easy to kill by any means.

Oriental cockroaches are very good at scattering when they sense human presence and they can float, so don’t try to flush them down the toilet or drown them.

They are quite persistent, so it often feels like an endless fight when you’re trying to get rid of them. However, with patience and consistent efforts, you can get rid of oriental cockroaches on your own.

How to get rid of oriental cockroaches

Identifying Oriental Cockroaches

To deal with an oriental cockroach infestation, you first need to know how to identify them first. Here are the various characteristics of oriental cockroaches:

Appearance: Their large size is the most distinct part of their appearance. They are about 1 inch long but can grow much bigger. Female cockroaches are usually larger than males.

They have a dark, shiny exoskeleton which can vary a little in color. Baby oriental cockroaches are lighter in color, almost a reddish-brown which darkens which age.

They seem thin because of their length and have six legs like all other cockroaches. Male oriental cockroaches have wings while females don’t, but neither of them can fly.

Smell: The easiest way to identify an oriental cockroach infestation is by smell. They have a very strong and musty odor that pervades every surface they touch.

In fact, they communicate with each other through smell, so the odor is pretty noticeable. If your basement or bathroom suddenly starts smelling foul and musty, it could be because of oriental cockroaches.

Abilities: Oriental cockroaches are one of the most persistent pests on the planet. It is near impossible to completely get rid of their population, but one can significantly reduce their numbers.

Even though they are sometimes called waterbugs, they cannot swim. However they do float, so you cannot get rid of them with water. Oriental cockroaches have short wings but thankfully they can’t fly or even jump long distances.

They can’t climb up walls like other cockroach species can. Oriental cockroaches prefer sticking close to the ground and usually try to keep themselves hidden.

Signs You Have an Oriental Cockroach Infestation

The best way to confirm an oriental cockroach infestation is by sight. If a large, dark brown or black cockroach with wings is scurrying around in your house, you have an oriental cockroach infestation.

They are most likely to be seen near pipes, toilets, sinks, drains, and sewer grates. They usually set out in pursuit of food, so you might catch them taking a trip to your kitchen or garbage can.

Oriental cockroaches reproduce by laying eggs, so you’ll probably notice their eggs in a sheltered, warm spot in your house. The eggs are also dark and arranged vertically in a capsule in pairs.

The eggs are abandoned by the female cockroaches and hatch on their own. The baby cockroaches emerge from the eggs and start eating whatever they can find. It can take up to a year for them to grow to their full size.

You can also identify an oriental cockroach infestation by their poop. It doesn’t look any different than regular cockroach poop, except it is a little larger. Oriental cockroach poop is roughly the same size as a grain of rice and is shaped cylindrically.

Pregnant oriental cockroach on a hand

How to Get Rid of Oriental Cockroaches

Here are step-by-step instructions on how to get rid of oriental cockroaches:

Step One: Preparation

Before you actually get down to exterminating oriental cockroaches, you need to make a few preparations to ensure that they don’t escape.

First of all, make the environment less homely for them by removing all leftovers and trash.

If there are any leaky pipes or taps, fix them to make the surroundings less damp. Air out all the rooms and make sure there is proper airflow to lessen the humidity inside the house.

Next, you need to ensure that there are no escape routes for the oriental cockroaches. Seal off all cracks and holes that lead outside. Oriental cockroaches are large but they can wriggle into holes half their size, so be very thorough.

Step Two: Go for the Kill

Once the initial preparations are done, you can start the extermination process. The most common method is to use a roach spray. Spray it directly on the oriental cockroaches whenever you see them.

Most roach sprays are highly successful in killing oriental cockroaches indoors. They should start dying a few seconds after you spray them.

Foggers are another option. However, they are far less convenient as you cannot enter the room for several hours if you set off a fogger. In comparison, sprays take less time and can be aimed effectively at all the nooks and crannies of your house.

If you have a sizeable oriental cockroach infestation, we suggest you use bait. They are good for large colonies and less harmful for the humans in the house. People who don’t want to expose their kids and pets to pesticides usually prefer using bait.

The bait works by attracting oriental cockroaches who eat the pesticides and die later. Due to the delay between eating the pesticide and dying, the cockroaches infect other cockroaches too.

Keep baits in all the dark, damp, and humid areas of your house like kitchen cabinets, basements, and attics.

Step Four: Sprinkle Insecticidal Dust

After the initial extermination, spread insecticidal dust on all the affected areas. The great thing about it is that it can reach all the inaccessible areas of your house.

Spread insecticidal dust on all the hard-to-access spaces like the spaces between the wall and the furniture, under furniture and appliances, and any other crevice.

Step Five: Prevent Their Return

Once all the living oriental cockroaches are gone, you want them to stay that way. You can use a residual spray to make sure they don’t make a reappearance in your home.

Residual sprays last for months and keep exterminating oriental cockroaches long after their application. Since there is no surefire way of knowing if you’ve completely exterminated the oriental cockroach infestation, using a residual spray is a good idea.

The residual spray will need to be applied again after a period of three months. It does a good job of keeping cockroaches away and out of your house.

There might be oriental cockroaches or other pests outside your house but the spray will discourage them from entering your home.

Step Six: Cleanup

Now that all the cockroaches are gone, you need to clean your house to keep it free of pests. No pesticide is as effective as cleanliness, it makes your house a hostile environment for pests.

Clean and sanitize all the surfaces in your house. Fix any leakages in the house and clean rarely used spots like attics and basements. Make sure you don’t leave out any food or trash for too long. Take the garbage out on time.

Following all these steps should keep your house a pest-free zone for the foreseeable future.

Getting Rid of Oriental Cockroaches Outdoors

Oriental cockroaches usually live outdoors. They choose moist areas like damp logs, piles of leaves, and mulch beds to make their home. They venture into your home in search of food or to protect themselves from the cold during winter.

Getting rid of oriental cockroaches outdoors is not that different. Choose a good residual spray and use it along the perimeter of your house. Go up to three feet out from the perimeter.

Don’t miss all the doors and windows. If the plumbing of your house branches outdoors cover this area too.

It also bodes well to place bait outside the house. They will run out of your house and go straight to the baits outside. The baits will catch all the cockroaches that escape and you won’t have to fear a re-infestation.

Natural Ways to Get Rid of Oriental Cockroaches

If you don’t want to use pesticides, there are a few natural options you can consider. Here’s how to get rid of oriental cockroaches naturally:

Baking Soda: Baking soda is fatal to oriental cockroaches when ingested. Their stomachs can literally burst when they drink water after ingesting baking soda.

You need to make sure they consume it. One way is to mix it with sugar and leave it in places you’ve spotted oriental cockroaches.

Baking soda for cockroaches

Diatomaceous Earth: DE is also very harmful to oriental cockroaches. To make sure it isn’t harmful to your family or pets, check the label to make sure it is food-grade DE.

Sprinkle it in all the spots you’ve caught sight of oriental cockroaches. It will damage the cockroach’s exoskeleton when it comes in contact with it and the cockroaches will eventually die.

You can also mix it with sugar to make the oriental cockroach ingest it.

Boric Acid: Boric acid is poisonous to oriental cockroaches. You can create a makeshift bait by putting some boric acid on organic waste like fruit peels. Oriental cockroaches will be attracted to it and ingest the poison.

Essential Oils: Oils cannot kill cockroaches. But they do act as a repellent. Spraying essential oils around your house will drive away oriental cockroaches.

Peppermint, lemongrass, and cypress oil are all good choices to repel oriental cockroaches. You can even mix them up to create a more potent repellant.

Essential oils

Preventing Cockroach Infestations

There is no specific action you can take to prevent an oriental cockroach infestation. The most important thing to do is to keep your home clean. A clean house is not attractive to oriental cockroaches.

The two most attractive things to oriental cockroaches are food and moisture. If the pipes or taps in your house are leaky or there are damp spots in your attic or basement, oriental cockroaches will make a beeline for those spots.

Food is a huge motivator for oriental cockroaches to move indoors. If there are leftovers lying around and you always leave the trash out for too long, oriental cockroaches will be attracted to your home.

Another way to prevent an oriental cockroach infestation is through scents. There are some common household items that repel oriental cockroaches. Use the following scents to repel cockroaches:

  • Cinnamon: Cinnamon is one spice that all insects hate. You can sprinkle cinnamon powder at entry points like gaps or holes and it will repel insects from entering your house.
  • Pandan: Pandan is a plant whose leaves have a very distinct aroma. You can make a small pouch of dried-up pandan leaves and place them around the house to discourage cockroaches.
  • Vinegar: Vinegar is a natural insecticide. It is not effective in killing oriental cockroaches, but its pungent aroma discourages cockroaches from living in your home.
  • Bay Leaves: Most insects do not like the scent of bay leaves. You can place a bay leaf around cabinets and oriental cockroaches will keep away from them. It is a good way to prevent food contamination.

    You can also crush dried bay leaves and mix them in the topsoil of your garden or backyard to discourage pests from entering your property.


What Kills Oriental Cockroaches?

There are many different cockroach sprays and foggers you can use to kill oriental cockroaches. After the primary extermination, use insecticidal dust and residual spray for a thorough extermination.

Oriental cockroaches are quite persistent and you will need to reapply insecticidal dust or residual spray a couple of times.

If you do not wish to use pesticides, there are a few natural options you can consider. Baking soda and boric acid are both poisonous to oriental cockroaches. Mix either one with sugar and leave it in spots frequented by oriental cockroaches.

Diatomaceous earth is also a natural solution for oriental cockroaches. Spread it around the areas of your house infested by oriental cockroaches. Coming in contact with DE will be eventually fatal to cockroaches.

You can also use essential oils like peppermint and lemongrass to repel cockroaches. Vinegar, cinnamon and bay leaves are also natural repellants that discourage oriental cockroaches.

Do Oriental Cockroaches Bite?

Technically, they could bite humans if they wanted to, but it is quite rare. Like most insects, they are more afraid of humans than humans are of them.

It would take a humongous infestation to reach a situation where oriental cockroaches start biting humans. What’s far more dangerous to humans is food contamination and the passing of harmful pathogens.

What Attracts Oriental Cockroaches Indoors?

Oriental cockroaches are outdoor creatures. There are a few basic reasons they move into human dwellings. They are either attracted by the damp environment inside the house or by rotting food lying around.

Low temperatures during winners are also a motivating factor, but they would still need a suitably moist environment and food to survive indoors.

If you make sure these two situations don’t develop in your house, oriental cockroaches will keep away. General cleanliness is enough to discourage them from stepping into your home.

Wrapping Up

Dealing with an oriental cockroach infestation is an incredibly pesky affair. They are extremely persistent and require multiple rounds of extermination to exit your home.

You need to follow up with insecticidal dust and residual sprays to kill all the remnants of the infestation. Most people go the extra mile and use natural repellants like peppermint oil, cinnamon, and bay leaves to keep the cockroaches at bay.

Natural insecticides like boric acid and baking soda can also be used to exterminate oriental cockroaches. It might take a little while longer as it is a less targeted approach.

With oriental cockroaches, prevention is truly better than cure. Keeping your surroundings fresh and clean means you’ve already won half the battle against pests. It is also more sanitary and hygienic.

We hope this guide helps you successfully exterminate the oriental cockroach infestation in your home.

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