Using Boric Acid To Kill Cockroaches – 5 Ways

Roaches. They are fast, difficult to catch, and will enter your home at will! There are tons of things that attract a roach to your home, and maybe, just maybe, you can use some of that knowledge to help get rid of them! There are natural ways that can deter roaches, such as tea tree oil or mothballs. There are also some things around your home (apart from your shoes) that can kill cockroaches, such as bleach. In this post, we will look at ways you can use boric acid to kill cockroaches!

Always follow instructions when using boric acid, as it is a poison and can cause health problems, especially if ingested.

What you will learn in this post:

  1. What boric acid is
  2. 5 ways of using boric acid to kill cockroaches
  3. Answers to frequently asked questions

Using Boric Acid To Kill Cockroaches

What Is Boric Acid

Boric acid is a substance commonly used in the following capacity:

  • Pest control
  • Antiseptic
  • Anti-fungal

It is naturally occurring and is most commonly found in:

  • The sea
  • Volcanic regions

Can You Use Boric Acid To Kill Roaches?

Yes, you absolutely can use boric acid to kill cockroaches! It has been used for many years and is even used by professionals.

Boric acid is an awesome roach killer for 3 reasons:

  1. It breaks down the tough roach body.
  2. It disrupts the digestive system and severely dehydrates the roach.
  3. If a roach eats another roach killed with boric acid, the cycle begins again!

These are the reasons why boric acid is one of the best natural roach killers you can buy!

5 Ways Of Using Boric Acid To Kill Cockroaches

5 ways of Using Boric Acid To Kill Cockroaches Infographics

1. Make Boric Balls

One tip is to make balls of tasty food for the roaches. There is one hidden ingredient they won’t enjoy… not in the long to medium term anyhow. That is boric acid!

The good news for you is that cockroaches literally eat anything! They have a preference for sweet tuff (don’t we all?), so use that to your advantage.

Make tiny boric balls with the following ingredients:

  1. 1/2 cup of flour (any flour)
  2. 1/2 cup boric acid
  3. 1/4 cup sugar
  4. 1/4 cup milk

Mix the ingredients until you get a pie-like consistency. Break out tiny chunks of the mixture and roll them into balls. Place them around your home where you have noticed roach activity.

2. Make Boric Spray

Another option is to add the boric acid to a water spray bottle to use as and when you need to.


  • 1/2 cup boric acid
  • 1 pint of water

Make sure it is mixed thoroughly. Spray this mixture in all areas where you have seen roach activity. Also, if you are a good shot, you should be targeting direct hits on a roach! It is a skill that required quick reflexes, a sharp eye, and tremendous athletic ability!

3. Scatter Powder

This is probably the easiest method of using boric acid to kill cockroaches!

Scatter the boric acid in areas where you have seen roaches or in areas where there is a supply of food or water. Many things attract roaches to your home, so use that knowledge to understand where you need to put the boric acid.

The roaches will scurry through the powder, which sticks to their feet. Roaches groom themselves regularly to remove debris from their feet. They do this by running feet through their mouth. Bingo… the roach consumes the boric acid!

4. Add To Traps

If you have roach traps set up around your home, you should scatter boric acid around the trap entrance and inside the trap (if you can).

Some traps have roach bait inside, so roaches are already drawn by the scent. As they approach the bait station, they will get boric acid on their feet which is consumed as part of the grooming process (see above).

If the roach enters the trap, the boric acid is just another thing that will kill them!

5. Mix Into Water

Roaches need water. In fact, it is one of the things that roaches look for while they scurry around your home.

You could leave trays of ‘boric acid’ water in areas where you have noticed roach activity, as they will be drawn to these.

The water should contain boric acid. When the roach drinks the water, the boric acid is consumed.

Use the same mix as above:

  • 1/2 cup of boric acid
  • 1 pint of water

Mix thoroughly and separate into a few trays. Scatter these trays around your home.

Frequently Asked Questions

What do you mix with boric acid to kill roaches?

To make boric balls (used as roach bait) I use 1/2 cup of flour, 1/2 cup of boric acid, 1/4 cup of sugar, and 1/4 cup of milk. Make these into balls and use them as cockroach bait. If you are going to make up a spray, use 1/2 cup of boric acid, and 1 pint of water. Mix thoroughly before using it.

How long does it take for boric acid to kill roaches?

If a roach ingests boric acid, it will usually die within 72 hours.

Where can I buy boric acid to kill roaches?

You can buy boric acid from many of the big stores, or you can buy it online at eBay and other similar sites.


Using boric acid to kill cockroaches has been a part of roach control for several years. In this post, I have given you 5 ways that you can use it.

Once you have made the boric balls or made up the spray, you need to know where to use it. Here is a quick bullet point guide. Use boric in the following places to kill roaches:

  • Near a water supply – Any leaking pipes or small accumulations of water.
  • Food supplies – if you cannot store food in roach-proof containers, it will be a target. Use boric acid near these places.
  • Entrance points – check around your home for entry points that a cockroach can use to gain entry. Looks for small cracks near window openings, etc.

The good thing about boric acid is that it is used to tackle many pests, not just cockroaches! You can use it for ants, bed bugs, and even silverfish.

One last thing – boric acid kills roaches, but it doesn’t deter them! You can use things like tea tree oil or mothballs to deter roaches.

Good luck!


About the author

DIY Pest Control Enthusiast Since 1996

After spending the entire night lying awake in a cockroach-infested hotel, I have driven myself to build knowledge on all things pest control. Since then, I've tested pest control techniques to see what works and what doesn't. Now, here I am giving you all the info I have learned!

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