# Why does boric acid have such a great effect on roaches?
**URL:** https://boards.straightdope.com/t/why-does-boric-acid-have-such-a-great-effect-on-roaches/424421
**Category:** Factual Questions
**Created:** [October 29, 2007, 6:00am UTC](https://boards.straightdope.com/t/why-does-boric-acid-have-such-a-great-effect-on-roaches/424421 "2007-10-29T06:00:42Z")
**Posts on this page:** 19
**Page:** 1
### Author:  [@Just\_Some\_Guy](https://boards.straightdope.com/u/Just_Some_Guy)
#### Post date: [October 29, 2007, 6:00am UTC](https://boards.straightdope.com/t/why-does-boric-acid-have-such-a-great-effect-on-roaches/424421/1 "2007-10-29T06:00:42Z")
Oh great Dope, knower of the unknowable and source of convenient answers to all of life’s complexities I must ask you: what exactly does boric acid do to cockroaches?
Twenty-five years ago the master offered these two alternatives for how boric acid does its voodoo on cockroaches so well:
> [@Cecil Adams](#):
>
> (1) The stuff gets on the waxy coating on the critter’s hide (or “exoskeleton”) and partially dissolves it, whereupon the cockroach dehydrates and croaks.
>
> (2) The borax acts as an abrasive, causing microscratches in said coating. Cockroach dehydrates, etc.
Surely someone has done some research into this since 1983. Unfortunately information on the internet for this is sketchy and I’m concerned that a lot of it might be tainted by “common knowledge” rather than using actual research. So is there a definitive answer?
If there isn’t I’ll just pick one of those two. I’ve got a 50/50 shot at least.
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### Author:  [@Blake](https://boards.straightdope.com/u/Blake)
#### Post date: [October 29, 2007, 8:25am UTC](https://boards.straightdope.com/t/why-does-boric-acid-have-such-a-great-effect-on-roaches/424421/2 "2007-10-29T08:25:51Z")
[QUOTE=Just Some Guy]
If there isn’t I’ll just pick one of those two. I’ve got a 50/50 shot at least.
[/QUOTE]
Nope, both are almost certainly wrong.
There hasn’t been much research done into the mode of action of borax for cockroaches because there is no money in it, however it has been well researched for many other pests of greater economic concern. In all those cases boron acts as a poison that inhibits enzyme production in the stomach as well as interfering with the signals controlling appetite. There is no reason to assume that exactly the same mode of action doesn’t applk to roaches. The roaches walk over the stuff and pick it up in their legs, they then swallow it when they groom themselves. The animals loses the ability to digest food as well as ceasing to eat or drink. Death follows rapidly but it has nothing nothing whatsoever to do with damaging the cuticle.
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### Author:  [@DrFidelius](https://boards.straightdope.com/u/DrFidelius)
#### Post date: [October 29, 2007, 1:22pm UTC](https://boards.straightdope.com/t/why-does-boric-acid-have-such-a-great-effect-on-roaches/424421/3 "2007-10-29T13:22:18Z")
(Works on ants, too. I get them into the stuff by mixing it with some corn meal and white sugar. Small amounts in shallow receptacles [yogurt lids] stopped an infestation this summer in less than a week.)
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### Author:  [@guizot](https://boards.straightdope.com/u/guizot)
#### Post date: [October 29, 2007, 1:52pm UTC](https://boards.straightdope.com/t/why-does-boric-acid-have-such-a-great-effect-on-roaches/424421/4 "2007-10-29T13:52:27Z")
[QUOTE=Blake]
In all those cases boron acts as a poison that inhibits enzyme production in the stomach as well as interfering with the signals controlling appetite. …The animals loses the ability to digest food as well as ceasing to eat or drink. Death follows rapidly but it has nothing nothing whatsoever to do with damaging the cuticle.
[/QUOTE]
This is my understanding as well. If OP has a problem with roaches, s/he should try to get “Miraculous Insecticide Chalk.” It’s essentially boric acid powder pressed into the shape of chalk sticks. It’s easy to apply: draw a line on surfaces where roaches have to go. Once applied, it’s finer than your typical boric acid product, so it gets on roaches more. Also it’s really cheap.
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### Author:  [@WhyNot](https://boards.straightdope.com/u/WhyNot)
#### Post date: [October 29, 2007, 2:53pm UTC](https://boards.straightdope.com/t/why-does-boric-acid-have-such-a-great-effect-on-roaches/424421/5 "2007-10-29T14:53:31Z")
[QUOTE=DrFidelius]
(Works on ants, too. I get them into the stuff by mixing it with some corn meal and white sugar. Small amounts in shallow receptacles [yogurt lids] stopped an infestation this summer in less than a week.)
[/QUOTE]
Anyone know if this would be safe to do in a home with cats? Will boric acid kill the cats like it will the ants?
ETA: Never mind, found my own answer:
> [@](#):
>
> Borate, or boric acid is used as a homemade insecticide. It has a low oral toxicity.
>
> Signs: Vomiting, diarrhea, anorexia, CNS depression, muscle weakness, ataxia, and possible seizures.
>
> Treatment: The problem with this poisoning is that activated charcoal does not absorb it, the only way to get it out of the system is through dialysis.
> **[Plants Poisonous to Livestock - Cornell University Department of Animal Science](http://poisonousplants.ansci.cornell.edu/toxcat/toxcat.html)**
>
> Department of Animal Science at Cornell University; This site contains information about plants which are poisonous to or adversely affect animal health.
It might be “low”, but my crazy cat lady friend won’t endanger her kitties to get rid of the ants eating their cat food.
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### Author:  [@rocking\_chair](https://boards.straightdope.com/u/rocking_chair)
#### Post date: [October 29, 2007, 11:52pm UTC](https://boards.straightdope.com/t/why-does-boric-acid-have-such-a-great-effect-on-roaches/424421/6 "2007-10-29T23:52:24Z")
the nifty new recycled denim insulation is impreg. with boric acid. something to keep in mind if you are bug phobic and insulating your house.
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### Author:  [@Punoqllads](https://boards.straightdope.com/u/Punoqllads)
#### Post date: [October 30, 2007, 12:39am UTC](https://boards.straightdope.com/t/why-does-boric-acid-have-such-a-great-effect-on-roaches/424421/7 "2007-10-30T00:39:53Z")
Dissolve the borate/boric acid into some citrus soda if you’re worried about cats. The syrup in the soda will attract the ants while the citrus flavor will repel the cats.
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### Author:  [@Rusalka](https://boards.straightdope.com/u/Rusalka)
#### Post date: [October 30, 2007, 6:14am UTC](https://boards.straightdope.com/t/why-does-boric-acid-have-such-a-great-effect-on-roaches/424421/8 "2007-10-30T06:14:34Z")
I thought Boric acid only works when it’s in crystal form, and dissolving it in water renders it ineffective?
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### Author:  [@Myglaren](https://boards.straightdope.com/u/Myglaren)
#### Post date: [October 30, 2007, 7:02am UTC](https://boards.straightdope.com/t/why-does-boric-acid-have-such-a-great-effect-on-roaches/424421/9 "2007-10-30T07:02:21Z")
You can buy it here as a commercial product where it is dissolved in a honey-like syrup that attracts the ants. They supply a couple of small ‘cassettes’ that keep it away from pets & kids but there are small holes big enough to admit ants but nothing larger.
Can’t remember the name though.
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### Author:  [@Myglaren](https://boards.straightdope.com/u/Myglaren)
#### Post date: [October 30, 2007, 6:13pm UTC](https://boards.straightdope.com/t/why-does-boric-acid-have-such-a-great-effect-on-roaches/424421/10 "2007-10-30T18:13:18Z")
This is it - [Nippon Ant Killer Liquid](http://www.ciao.co.uk/Nippon_Ant_Killer_Liquid__5154976)
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### Author:  [@WhyNot](https://boards.straightdope.com/u/WhyNot)
#### Post date: [October 30, 2007, 6:20pm UTC](https://boards.straightdope.com/t/why-does-boric-acid-have-such-a-great-effect-on-roaches/424421/11 "2007-10-30T18:20:38Z")
[QUOTE=Myglaren]
This is it - [Nippon Ant Killer Liquid](http://www.ciao.co.uk/Nippon_Ant_Killer_Liquid__5154976)
[/QUOTE]
Thanks for taking the time to look it up. Unfortunately, it looks like it’s not available here. But I will look on the shelves for a similar product, now that I know one exists; perhaps there is another manufacturer distributing it here.
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### Author:  [@Blake](https://boards.straightdope.com/u/Blake)
#### Post date: [October 31, 2007, 8:29am UTC](https://boards.straightdope.com/t/why-does-boric-acid-have-such-a-great-effect-on-roaches/424421/12 "2007-10-31T08:29:40Z")
[QUOTE=WhyNot]
Thanks for taking the time to look it up. Unfortunately, it looks like it’s not available here. But I will look on the shelves for a similar product, now that I know one exists; perhaps there is another manufacturer distributing it here.
[/QUOTE]
Just make some yourself. 5 parts sugar to 1 part borax dissolved in minimal (warm) water. If you wish to discourage cats then as punqolads suggested add a couple of drops of lemon essence..
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### Author:  [@WhyNot](https://boards.straightdope.com/u/WhyNot)
#### Post date: [October 31, 2007, 12:40pm UTC](https://boards.straightdope.com/t/why-does-boric-acid-have-such-a-great-effect-on-roaches/424421/13 "2007-10-31T12:40:02Z")
[QUOTE=Blake]
Just make some yourself. 5 parts sugar to 1 part borax dissolved in minimal (warm) water. If you wish to discourage cats then as punqolads suggested add a couple of drops of lemon essence..
[/QUOTE]
Thanks! That’s a recipe I can use!
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### Author:  [@Pleonast](https://boards.straightdope.com/u/Pleonast)
#### Post date: [October 31, 2007, 2:53pm UTC](https://boards.straightdope.com/t/why-does-boric-acid-have-such-a-great-effect-on-roaches/424421/14 "2007-10-31T14:53:13Z")
What would be the effects of that substance on a human?
Not to be a worry-wart or anything, but the results of that recipe will look, smell and perhaps taste similar candy.
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### Author:  [@bordelond](https://boards.straightdope.com/u/bordelond)
#### Post date: [October 31, 2007, 3:42pm UTC](https://boards.straightdope.com/t/why-does-boric-acid-have-such-a-great-effect-on-roaches/424421/15 "2007-10-31T15:42:37Z")
[QUOTE=Pleonast]
What would be the effects of that substance on a human?
Not to be a worry-wart or anything, but the results of that recipe will look, smell and perhaps taste similar candy.
[/QUOTE]
That link in **WhyNot’s** post about requiring dialysis to remove the stuff from the body makes it look like a fairly serious brand of poisoning … even if it doesn’t kill.
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### Author:  [@redtail23](https://boards.straightdope.com/u/redtail23)
#### Post date: [October 31, 2007, 3:55pm UTC](https://boards.straightdope.com/t/why-does-boric-acid-have-such-a-great-effect-on-roaches/424421/16 "2007-10-31T15:55:14Z")
[QUOTE=WhyNot]
Thanks for taking the time to look it up. Unfortunately, it looks like it’s not available here. But I will look on the shelves for a similar product, now that I know one exists; perhaps there is another manufacturer distributing it here.
[/QUOTE]
For those of you who want the manufactured packets, it’s [Terro](http://www.terro.com/).
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### Author:  [@BobMmm](https://boards.straightdope.com/u/BobMmm)
#### Post date: [October 31, 2007, 4:19pm UTC](https://boards.straightdope.com/t/why-does-boric-acid-have-such-a-great-effect-on-roaches/424421/17 "2007-10-31T16:19:52Z")
I like the fact the roaches don’t seem to develop an immunity to Boric acid, like other things that kill them. Actually I don’t know they don’t but boric acid for roaches goes so far back you think if roaches could develop an immunity they would’ve done so by now.
Is this true BTW and if so why?
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### Author:  [@Grrr](https://boards.straightdope.com/u/Grrr)
#### Post date: [October 31, 2007, 9:26pm UTC](https://boards.straightdope.com/t/why-does-boric-acid-have-such-a-great-effect-on-roaches/424421/18 "2007-10-31T21:26:19Z")
Nothing to add here except that I just recently discovered that Gold Bond body powder is pure sadistic evil to little critters.
I had a small (left over) pile of this stuff sitting on the bed of my bath tub. I came home from work to have lunch. I went to the bathroom to take a leak. While doing my business I happened to notice a little crawly had made it’s way over the pile of powder, then about six steps out of the powder; it turned over on it’s back and died…
…Or so I thought. I was in a rush to get back to work so I didn’t have time to pick it up and flush the critter away. So six hours later I get home from work and immediately go to the bathroom to dispose of the bug. When I did, I noticed the poor things legs where still moving!
I thought to myself: “Damn! It sucks to be you. A six hour painful death to be ended only by being flushed down a toilet.”
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### Author:  [@Mister\_Rik](https://boards.straightdope.com/u/Mister_Rik)
#### Post date: [October 31, 2007, 9:50pm UTC](https://boards.straightdope.com/t/why-does-boric-acid-have-such-a-great-effect-on-roaches/424421/19 "2007-10-31T21:50:20Z")
On a similar note, what’s up with ants and orange peel? When we had an any problem a couple years ago, my roommate took fresh orange peel and smeared it around the areas where the ants were. Very soon, we had no ants.