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Does Bed Bug Spray Kill Roaches?

If you have a roach problem, you may be wondering if you can use the old bed bug spray you have lying around.

Yes, bed bug spray usually will kill roaches. Yet, the overall effectiveness of a particular bed bug spray on roaches depends on the chemicals in the pesticide. So, overall, it is always best to use an insecticide made for cockroaches to kill them. 

Can I Use Bed Bug Spray to Kill Roaches?

A white bed bug spray on a blue wooden table and with a blurred bed in the background.

Well, whether a bed bug spray will kill roaches and how good of a job it will do depends on the product. 

Typically, bed bug sprays contain pyrethrins and pyrethroids, which will kill roaches. 

Yet, these chemicals aren’t the best thing to use if you’re trying to get rid of cockroaches. 

The problem is that pyrethrin and pyrethroids won’t kill roaches after the spray has dried. 

But, since it takes between four and six hours for bed bugs spray to dry, you probably can kill a decent amount of roaches during this time as long as they walk directly over the wet insecticide. 

How Do Pyrethrins and Pyrethroids Kill Roaches?

Pyrethrins and pyrethroids kill cockroaches in the same way they do bed bugs. 

Basically, both of these chemicals disrupt an insect’s nervous system. 

More specifically, they delay the sodium channels in nerve cells, which makes the nerves fire continuously. 

And when an insect’s nervous system doesn’t stop firing, it causes paralysis and death. 

How to Use Bed Bug Spray to Kill Roaches 

The best way to kill roaches with bed bug spray is to spritz it directly on them. 

Basically, a cockroach walking through wet bed bug insecticide may or may not die from it. 

Also, roaches usually avoid pesticides, so many of them won’t crawl through the spray. 

Thus, applying the bed bug spray directly to the roach is always best. 

However, though, anyone who has had roaches knows they can be hard to catch. 

So, if you are going to use bed bug spray to kill roaches, you should first set out roach traps. 

Then, when the roaches get stuck in the trap, you can spray them to kill them faster. 

Or, if you don’t have roach traps, the next best thing is to spray the roach spray into any cracks or crevices in your walls, floors, or ceiling since that’s where roaches like to hide. 

Staying Safe While Using Bed Bug Spray to Kill Roaches 

First and foremost, you should always read the instructions on the bottle before using insecticides. 

These products have to be toxic to kill insects, meaning they could harm you, your family, or your pets. 

So, be careful when using insecticides and follow some of these basic tips to keep all the humans and animals in your home safe: 

  • Do not allow the pesticide to make contact with your skin. 
  • Be careful not to get the pesticide in your eyes or mouth. 
  • Do your best not to breathe in the pesticide. 
  • Immediately wash your hands after using the pesticide. 
  • Keep children and pets out of the room until the pesticide completely dries. 
  • Remove or cover food before you spray any pesticide. 
  • Remove children’s or pet’s toys from the area before you spray. 
  • If you have leftover pesticide, store it properly in a place where children or pets can’t accidentally access it. 

And finally, if you or one of your pets or family members comes into inappropriate contact with the pesticide, call poison control immediately for further guidance. 

What Kills Roaches the Best?

Close-up photo of a dead cockroach on the floor.

Boric acid will work the best at killing roaches. 

Boric acid, or Borax, works on roaches quickly and effectively by disrupting their nervous system and digestive tract. 

Basically, when you put down boric acid, the roaches crawl over it and get the chemical all over their bodies. 

They will then consume the boric acid when they try to clean it off themselves. 

Then, once inside the roach, the pesticide begins to destroy its insides until the insect finally dies. 

How Do I Use Boric Acid on Roaches?

Boric acid typically comes in a powder, which you should spread across places where roaches frequent, like countertops. 

Generally, it’s best to use boric acid at night because this is when cockroaches are the most active. 

You should leave the acid out until morning and then vacuum up the remaining powder. 

Afterward, thoroughly wipe down any surfaces where you placed the powder with a wet rag. 

And again, make sure you follow all the instructions on the container and do not let children or pets near the insecticide. 

How Long Does it Take Insecticides to Kill Roaches?

A spray bottle releases chemicals into the air.

How long it takes for an insecticide to kill roaches depends on the type of pesticide you’re using and its active ingredients. 

Typically, if you spray a roach directly with either roach or bed bug spray, it will die within a few minutes. 

However, other treatments that are less direct, like boric acid, take about 24 hours to kill a roach after consumption. 

How Long Does it Usually Take to Eliminate a Roach Infestation?

On average, it takes about two weeks to get rid of roaches with proper treatment. 

Roaches aren’t as dumb as we tend to think they are, so it could take several attempts to get a cockroach to fall for a trap or walk through an insecticide powder or spray. 

Therefore, you shouldn’t get discouraged if you still see roaches after your first attempts to get rid of them. 

Cockroaches are notoriously difficult to kill, so you will need diligence and patience to eliminate an entire colony. 

Can I Kill Bed Bugs and Roaches at the Same Time?

A woman exterminator treats the house with hot steam.

Yes, there are certain treatments that kill both bed bugs and roaches, and choosing a remedy that does away with both of them can save you time and money. 

And to kill both insects, you could use bed bug spray in areas the bugs frequent since it can eliminate both insects. 

However, heat is the best treatment to get rid of your bed bug and roach infestation. 

Neither bed bugs nor cockroaches can survive extreme heat. 

Bed bugs will begin to die at 118°F (48°C), while roaches require similar temperatures of between 115°F and 120°F (46°C and 49°C). 

A professional can perform a heat treatment for you by using strong heaters to raise the temperature in every inch of your home. 

Typically, an exterminator will bring your house’s temperature up to 140°F to 150°F (60°C to 66°C) for five or six hours. 

Treatments at these temperatures and lengths give you the best chance of getting rid of all the bed bugs and roaches in your home. 

How Much Do Heat Treatments Cost?

Heat treatments are not cheap. 

In the United States, you can expect to pay between $1 and $3 per square foot. 

Thus, if you want to treat your entire house, you’re looking at between $2,000 and $4,000. 

UK prices tend to run a bit cheaper at around £350 for three rooms. 


Overall, you can totally use bed bug sprays to kill cockroaches. 

Unfortunately, though, bed bug sprays don’t tend to work as well on roaches as actual roach sprays.