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Kill Cockroaches With Boric Acid

This is a response to this post about pesky cucarachas:

American Cockroach

Living in a small rustic house with three (sometimes five) college guys in Abilene, Texas, I wasn’t sure who was to blame for the cockroaches. Things weren’t exactly kept clean. But one summer, I stayed to work while others left town. The roaches didn’t leave with them.

I happened to run into the landlord and I mentioned the bugs. His response was unexpected. “Yeah, but don’t worry. They’re tree roaches. They just come inside to look for water.” He went on to explain that the typical cockroaches people worry about are a different, smaller kind. They get into your food, but these don’t.

To get rid of them, he suggested a unique attack. Let’s call it the banana borax blitz:

  • Step 1: Chop up a banana and leave it outside near where you think they might be coming inside.
  • Step 2: After midnight, go outside to check the banana. You should find more cockroaches than you ever wanted to see in one place.
  • Step 3: Lightly dust them with borax, or powdered boric acid. You can buy it at most grocery stores.
  • Step 4: Panic as they scatter. Beware, these things can and fly when disturbed!

When cockroaches clean themselves, they eat the powder. Death is swift. I actually watched a few slowly crawl away and flip over with a kind of cockroach kabuki gesture.

It turns out boric acid is well documented for killing roaches (although others suggest a more subtle approach). Four of the top 10 results on Google are from .edu’s.

84 replies on “Kill Cockroaches With Boric Acid”

Hey everyone, I think I’m at the beginning of roach infestation since I recently saw 3 roaches this month even though I kill them out n throw the died body. I’m still so scare of there are more than what I can imagine. Worst of all its an apartment which means I can only try to kick them out of my apartment for a period of time I guess but still worth to try.

My kitchen is very clean no food outside. Clean every time after cook. Still here they are. So they are big mature ones. Didn’t not see babies yet. I empty the kitchen today spray the kitchen like died with roach spray. Also call in a exterminator who will come in couple of days. Question: I bought boric acid today in drug store. I’m not sure is this the right kind of boric aci. It labels boric acids n it comes as white powder. Instead of saying for roach killing it says for temporary relief of cuts or burns….. Can anyone here tell me did I get the right powder or it doesn’t really matter as long as boric acid.

I also bought Bengal spray since I heard they are quite effective. Together with combat gel baits.

Am I on the right track? If I do all this would I manage to get rid of them in my apartment? I’m planing to use boric acid tmr everywhere in the apartment. Wish me luck.

N weird thing. Those roach only apprear in the kitchen. Not see one in any other places not even in the washroom. But to be sure I will dust powder in every room.

Luka – a plastic bottle, usually white or yellow, stands about 9 inches tall, and maybe 2 1/2 inches across the bottom. Full of white powder. That’s the stuff. The Bengal spray may knock the population down for awhile, but the stuff is not residual, nor does it get into the roach’s hiding places.

The boric acid will be taken into the roach’s hiding place by the roaches themselves, and the powder will be residual. That means, when eggs hatch, the babies are likely to be poisoned before they wander out to find your food.

Good luck!

Hey Paul,

I just moved into my.first place and I have been swing baby roachese around my fridge.before I moved in I was told that their.were no roaches. I put down combat. I put down boric acid in the living room and.closets when I saw a mature roach. I just dusted my whole apartment and found a whole behind the fridge. Underneath my apartment is a storage garage. I think they come up to find food. What can I do to fight this. It’s not an infestation but I would like to be proactive. I also believe I have hoarders above me. How can I fight them off and protect my apt from.the garage and hoarders?

If you believe that hole behind your refrigerator to be a route for invaders, then dust that hole. Spray your boric acid as high as possible inside that hole, trying to get a nice thick, visible coating of dust on all the woodwork inside the wall. When you’ve done your best to coat everything, look down, and you’ll probably have a nice coat of dust on everything below the hole already. If not, spray some more dust in there.

Apartments are tough, because you have no control over anything on the other side of your walls, your ceiling, and your own floor. But, any cracks, holes, crevices that might be used by insect to invade your own home can be coated with the dust. They may come in, but the trip will cost them their lives.

If you have access to the storage garage, you can dust down there too. If you don’t have access, then maybe you can ask the landlord to do so. If children don’t play there, and no pets are kept there, you can lay the dust on really heavy, and never worry about cleaning it up.

Save the money you would spend on combat – as I recall, it was pretty expensive. And, the roaches we were battling just ate it up, and came back for more. No bait, no poison, no preparation that I’m aware of is less expensive than boric acid, and none of them are residual. That basement area, if heavily dusted with boric acid, will remain deadly to the little creatures for years to come.

So, basically, just use the dust, and close down all the highways in to your home. The roaches will stop coming, eventually.


Hi, I have a similar problem. I live in an apartment with kids and dogs. I keep it very clean but i am having a problem with the roaches. I have put boric acid down in my kids room, some in the living room where it is dark and some in the kitchen., but now i am seeing them in the bathroom and in the master bedroom. WHY is this happening to me? Do i need to place the boric acid everywhere in the apartment including closets and restrooms as well. I just need some help. The holidays are approaching and i always cook for xmas. I just dont want to worry about having a roach problem while preparing my meals and getting ready for the holiday. I hope to hear something back soon. Thanks everyone for all the help on previous post. I dont know if it helps but i live in tomball tx.

Yes, Ma’am – you need that dust everywhere that is accessible to you. If you can get into any spaces that neighbor or surround your own apartment, you need to get into them, and dust. Any place that you fail to dust is guaranteed to be a thoroughfare for the nasty little bugs to get into your apartment.

Apartments are going to be harder to control than any house or mobile home, simply because you can’t gain access to all other apartments.

Cleanliness has nothing to do with roaches. You can clean til you drop dead, everything in your apartment can sparkle and shine – but if a neighbor has roaches, then so do you.

Do the bath, do under your sinks, if there are any access covers that you can open, then open them and dust behind them. Roaches don’t find anything to eat in most closets, but those closets provide nice, dark residential areas for them. Yes, dust every bit of the closets! If you can pry up or pry out any moulding or trim with your fingers, then dust behind those as well.

Do you have dry dog food? I know that roaches just LOVE that stuff! Try to place the dog food some place where you can dust all around the bag of food. The roaches zero in on that good-smelling food, so make them track through the dust to get to it. Any individual roach will visit once – when he grooms himself later, he’s dead!

Good luck, Nikki!

Thanks guys for all this information. I bought my first ‘starter’ pack today and am going to try it out tonight. I will be reporting every progress I make right here. Once again, thank you.

boric acid is the only 100% long term solution. it also takes out fishmoths, crickets, ants mites, fleas, ticks….
for those concerned about the toxicity of boric acid it might be prudent to remember that half a bucket of water is enough to drown in.
a previous poster asked where to get it in south africa, in most supermarkets, pharmacies and chemical outlets like protea.
south africa will soon have its own remedy,
God bless

Alright so I read your article. My husband and I never had a roach problem… Until our neighbors moved in next door! We live in New Mexico and small roaches seem to be the issue here… Being from Colorado I had never seen a roach in my life. Anyways once our neighbors moved in we are under the assumption that they had an infestation and called a contract exterminator to spray. Well now all of a sudden our pest free home is over run by the little buggers! Our first attempt was Ortho spray, which worked but for maybe under a week or so… And once again late night drinks of water have turned to freak outs once the lights went on. So now tonight is our first attempt with a mixture of Borax powder and a little pancake mix. We hope to be rid of them before our new baby comes into this world. Wish us luck!

hi gabrielle92, as far as i can surmise the roaches where not really ‘exterminated’ next door but just ‘flushed” out – some of which ending up in your dwelling. the borax on its own will kill them, better yet would be you use boric acid, but don’t worry, they will both kill them – mixed or unmixed!
God bless your baby!
In Christ

Success!! We’ve had a few little ones here and there, but it seems the population that was trying to take over my home is now diminished! The borax has worked along with the Gel bait! We’ve resorted to putting any kind of open food like cereals and sugars in plastic containers. And have had no problems opening up food and finding little living “surprises” Thank you all so much for the advice! hopefully they will no longer bother us or our new baby! Hurrah!! :)

Boric Acid destroys the lining of the gut of cockroaches. They basically starve to death after ingesting it. It’s cheap and much more effective than many expensive neurological pesticides.

hi css
no, some roaches fly anyway, whether they eat boric acid or not. if they ingested it before take-off they’ll surely die within 5-7 days.
in Christ Jesus

Hi, I bought boric bowder last week and applied it all over my kitchen. I left it for two days and today morning found few cockroaches in my hall and on ceilings. This is the first time iam seeing them in my hall :( and had seen them till now only in my kitchen.Is it because of the infestation that they moved to hall and ceilings?

hi nicky, it takes about 5 days for the boric acid to kill the roaches, for lab test results see here . the roaches you spotted could already be dying, alternatively they have a new harbourage in your ceiling. i would sprinkle some boric acid on top of the ceiling by entering it through the trap door. take note that roaches will not move to a place where there is no heat, food and water.
have a good one!
in Christ Jesus

Hi Gabreil,
Thanks for the quick reply. Today I found a few on my carpet but they couldn’t move much probably because of the warmth ! Think a good vacuuming should clean up !

hi nicky,
i do not know what temperatures you are talking about, but lab tests show that adult male german cockroaches die within less than 30 minutes at 49C and just under one hour at 43C. temperatures for american cockroaches need not be that high to result in death. if boric acid is introduced with the mentioned high temperatures death occurs faster. in all instances where heat treatment is applied roaches tend to flee to the coldest available places like cracks or crevasses. it sure is a good idea to vacuum them off the rugs.
it can do no harm to sprinkle a little boric acid unto your carpets and work it in with a broom – that way it will lie in ‘ambush’ for any critters that might stroll around ;-)
in Christ!

Boric acid has worked wonders for me as well. I’ve had to deal with the small ones that people worry about (german cockroaches). When I first moved into my house, you could see maybe 50 to 100s of them at night if you just flip on the light switch. It was insane. I was installing new hardwood floors, so what I did was apply the powder all around in the gap where the floor and the wall meets. New baseboards covered it up real nice. A couple of months of being an extreme clean freak and they were all gone.

Then a year later, I introduced some of them into my house again from a computer taken from a roach infested home. I didn’t have small children or pets, so I dusted half the kitchen floor with boric acid powder every night. It was a lot of work, but it was worth it. They were gone within a few weeks.

At the same time, there may be less than you think.
This extreme political process many have been responsible for
changing the meaning of the word exterminate. The pet water bowl is a safe location for cockroaches to hydrate

I moved to Las Vegas a few months ago. Live in a complex over 200 units. They of course have roaches. Ihaven’t had to deal with roaches in almost 29 years living in Wisconsin. But I did have problems with flying ants and used Boric. Acid successfully.I learned about Boris acid many years ago from a genius co-worker. I was managing 110 units of scattered rental housing. Big coach problems (Chicago) Now I have to use it here in LAs Vegas. It’s disgusting. I refused to let them
spray the chemicals. They looked so surprised. I haveto use table salt until I can get to the store for Boris acid and caulk postal any holes .

I”ve only seen a few adults. The table salt dehydration them when they clean themselves. It works well but Boris acid is the solution. Thank you and God bless you for sharing this remedy. PS you are right about the dust AND don’t mix it with anything. Let the dust do the work and spread the word. God always comes through! I.refuse to have them in my home.

I haven’t lived with cockroaches for many years. Moved into the nicest apartment complex. A week after being here i began to see them. Made a complaint to the apartment manager whom without me knowing it had a company come out to spray behind my refrigerator and use bait gel in my cabinets. I still went out and bought Roach Prufe boric acid. I see them coming from my bathroom and from the closet in my hallway where the hot water tank is located. I applied it along the baseboards in every room and closet, inside the cabinets, in every crack and crevice that i could find. I keep my apartment clean and keep my sinks dry. It’s been a few days and more of them are starting to show up but i read somewhere that you will see more before you see less. I am praying that this kills them. The anxiety is causing me to lose sleep and my appetite. Somebody pray for me.

A great short, specific and easy to read post, Nathan. It’s true, boric acid is fantastic at killing cockroaches – but not getting rid of them. In your case, if those really were tree cockroaches and not German, Oriental or North American ones, perhaps it worked. But if we are speaking about a household cockroach infestation, as a pest professional I don’t think it’s enough to simply repel the insects. How could you go on living, knowing there’s a cockroach nest on your property!
I did a job once in Newham, a client had a cockroach nest inside his SINK. so you see, boric acid just doesn’t cut it in such cases.

I wish I knew to get this boric acid powder info out to everyone everywhere..but maybe roaches, which will be alive even after nuclear war wipes humans off the planet will find a way to combat it! I live in a mobile home in a mh park in NC..lived here for 15 yrs and never saw ONE roach. This is good because I am a paranoid freak, an absolute crazy person when it comes to roaches. THEN disaster when some filthy women with SEVERAL cats and a dog moved next door about 2 months ago. They pile their garbage on their deck ..just feet from my house til I complain to manager. They obviously brought a million roaches with them because just days after they moved in, I started seeing one roach a week in my bath. I already knew about boric acid being the remedy but figured I was just getting a couple of wandering roaches coming in here, so I sprayed my yard and put some bug bombs under my house plus the boric acid everywhere. Nevertheless they keep on coming over!! I have sticky pads all over my bathroom and STILL find one stuck on there every few days. My only solution seems to be to some way get inside the neighbors mobile home and dust it!! I am thinking of writing a letter attached to a container of boric acid, apologizing for assuming the bugs are coming from their place but explainiing how this is the only solution! What do you think? My sister moved into a house years ago which was infested so badly, an exterminator who she called told her to forget about it when she gave her address since he had been summoned many times to kill the bugs to no avail. She used the boric acid powder and within a month, never saw another bug!!

I live in Tx, and OK prior to moving here. I have battled with German cockroaches for the last 6 yrs. My wife and I have tried bombs, combat gels, interior & exterior barrier sprays to which we have had little lasting results. I have also tried DE & Boric acid powder several times as well, the balls that some speak of seemed to have little effect attracting them. I wanted to share with everyone a recipe I am using now, and it seems to be doing the trick nicely. I buy those small tins of Vienna sausages, and mix about 1 1/2 links to one teaspoon of boric acid, and mix well with spoon. I add a few drops of honey, and put all over the house. The empty tins afterwards should have about an inch of juice on the bottoms; which I place those in dark corners behind furniture etc. It acts as a trap they circle the rim until they eventually fall and drown. It’s only been about 1 week, and daily I make small batches like described, and reapply the results are remarkable. I hope some of you will try this, and let me know if you have had similar results. Thanks.

Blogger Paul, this is an excellent blog post. It is amazing to me that here, nigh on nine years later, there are still folks posting comments that “recommend” a method that directly contradicts your advice (I’m looking at you Michael on December 18, 2015). I’ve seen Paul’s spot on advice corroborated by others at professional exterminator, university lab and home maintenance sites.

Paul is right.

Though some people have a hard time believing such a simple, uncomplicated, straight-forward, non-poisonous to mammals method can be so very effective, it just simply is and we mustn’t over-think it. Relax folks. Just do what Paul instructs, which he does extremely well, in an entertaining way.

I recently had two small cockroaches in as many weeks, likely Germans, crawl in through my second floor bedroom window which I leave open an inch in all except very hot/cold weather here in North East Texas. FYI, Texas has the most pest exterminators in the whole USA because this huge state has equally huge bugs in huge numbers. I’ve never had a roach problem here but about once a year, a roach takes a wrong turn and I see it. The pest control company sprays once a year and that usually works. I keep a can of Bug Stop around for the exceptions.

Well I caught the last one, doused the square of cardboard over the clear cup I got him in, turned it over, and let him sit in there overnight. The next morning he looked at me as if he missed me. Merde. I picked a differed pesticide and squirted it inside the cup, wet the cardboard and left him in it for several hours.

Bright eyed and bushy tailed, he mocked me. Gah. I toss him over the balcony rail into the lawn and hope he croaks before he spawns. Clearly, he has developed a tolerance for the latest retail poisons. Which is the reason why I now seek a better solution. Every site I’ve visited readily recommend boric acid powder, with the same specific instructions Paul has outlined.

This appeals to me largely because, clearly, roaches have not developed a tolerance against it. That is crucial.

Boric acid is a chemical humans have used for over a century to great benefit in more than one application. And it makes perfect sense. And it’s inexpensive. And it won’t make me sick while applying it or breathing the air in the same room.

So ignore any of the comments that go on and on about mixing it with food items, that suggest making pastes or building berms with it, for crying out loud. Vienna sausage juice will attract a lot more than roaches who will be far scarier to deal with and are unaffected entirely by the acid.

Less is more, people. Try a little finesse, a touch of restraint, simply follow the instructions and be patient. It sounds like noticeable results will be realized within 7-10 days, which is quite manageable. Once in a while, the interwebs does disseminate some solid info you can trust.

But don’t believe me or Vienna sausages. Do your own research and don’t rely on just one, two or even three sites. This is my 4th site so I’ve done my due diligence.

Thanks Paul and bon chance y’all.

Apologies, I thought Paul was the blogger. No worries, I thank Commenter Paul and the blogger Nathan. Both advise us well. Let’s help most of us take heed.

Well I’m completely roach free in my house now & bluntly / respectfully I’d say it was no thanks to this article, or the person who isn’t even kind whatsoever pointing me out. I hope you feel good about yourself. Question though!.. How can any of us judge someone’s results as if it were seen with their own eyes? I’m being honest & I didn’t mean to upset anyone. I thought this was a place we can share different things we’re doing to achieve the same results. Guess I was wrong huh? Seriously think & act for yourselves everyone. Of course your gonna want good advice / understand several methods / research, but more importantly whatever you do. Make sure to base it on what you see is working in your situation, because it may be different than mine, or anyone else’s. They are a very adaptable bug. Deep cleaning & daily maintenance did the job for us. No more bugs! In my first post I did say… lol! I put that stuff all over the house, but some took me too literally. I only put small dabs on tin foil behind furniture, closets, toilets, sinks, corners of cupboards etc; the darker the better. When there was only a few here and there I started mopping with hot water & baking soda once a day. Have a good weekend everyone.

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