How to Kill Ants Naturally with Diatomaceous Earth

If you’re having ant problems in your home and are wondering if Diatomaceous Earth (DE) is an ideal solution, you’re in the right place.

In this post we’ll go over everything you need to know about DE and how you can use it to treat ants in your home.

Let’s dive in!

Do Diatomaceous Earth Kill Ants?

Yes. Diatomaceous earth (DE) is fatal to ants and other insects.

It kills insects by desiccation (absorbing the outer cuticle layer of their exoskeletons).

For this to work, the ants must first come in contact with the DE.

Once the DE gets on the ants, it will remove the thin waterproof outer layer of insects on their bodies.

This process causes ants to dehydrate and eventually die.

Other than ants, Diatomaceous Earth effectively kills cockroaches, silverfish, mites, ants, etc.

What Is Diatomaceous Earth?

Before I tell you how to get rid of ants using DE, let’s start from the beginning–what is DE?

Diatomaceous Earth is a naturally occurring powder that is made from the remains of diatoms. 

Diatoms are a common micro-algae found in most water sources and soil around the world. 

The remains of diatomaceous earth consist of a substance called silica. 

The silica inside the diatomaceous earth is what gives DE it’s beneficial features. 

DE has many uses. You can use it to: 

  • Kill insects 
  • Inside food
  • Inside household products such as toothpaste

How To Use DE on Ants?

DE kills ants when via direct contact. 

As such, the best way to use it on ants is by spreading the powder where ants live and travel.

For this, I recommend using a bulb duster. Using one will allow you to reach narrow crevices and deep wall voids.

Keep in mind that DE is only effective when dry.

So, when using DE, make sure to clean the surface first to remove any water or grease.

If you’re applying DE in humid places such as in your bathroom or attic, I recommend turning on a fan to reduce moisture.


The most effective way to get rid of ants by applying the powder to areas where ants frequent.

Indoors you can apply DE to cracks, crevices, guidelines, and other areas you might find DE.

The most effective way to apply DE is using a bulb duster. A bulb duster will allow you to apply DE to hard to reach areas. It also a great way to keep your application organized and clean.

It’s essential that when you apply DE, the surface must be dry. Wet surfaces will render the DE ineffective.

Monitor DE after application. This will help you determine the activity level and whether it’s still effective.

1. Inspect/Monitor Your Home

Inspecting and monitoring your home is crucial to the effectiveness of DE. 

When inspecting your home, learn several things:

  1. Type of Ant
  2. Locate where ants are most active
  3. Find key entry points around your home

When inspecting your home, you must look in places where ants frequent. Although different ant species behave differently, there are places where nearly all ants frequent inside homes. 

Below are locations that ants frequent: 

  • Under appliances
  • Small cracks and crevices
  • Cabinet door hinges
  • Windows or door sills
  • Along walls or cabinets, guides, and baseboards.
  • Near sources of water
  • Corners of Sink
  • Under the sink
  • Corners of Walls
  • Corner of Bathtub
  • Top of walls (crown molding

Remember to inspect outside your house. Not all ants will nest inside your home. 

Certain ants may only enter your home to forage for food before returning to their nest. Inspecting outdoors can also help you find potential entry points. 

2. Apply Diatomaceous Earth

After inspecting your home, you can begin applying DE. 

You should apply DE to the areas of your home where ants were active. You should also apply DE inside any entry points. Any ants that enter or exit will eventually die. 

Indoor Application

The most common places to apply DE is inside your kitchen and bathroom

When applying indoors, you must make sure all surfaces are dry before application. 

This is especially important when applying DE under sinks, near bathtubs, or around the toilet. 

Apply a thin layer of DE to any location that you suspect ant activity. Thick layers will discourage ants from walking through because it’s too difficult. 

The best way to apply DE indoors is by using a bulb duster. Using this, you can easily apply DE:

  • Under appliances 
  • Inside wall and cabinet voids
  • Inside cracks and crevices
  • Along baseboards
  • Around window sills 
  • Inside entry or exit points 

Avoid placing DE: 

  • In open walkways where it can be suspended into the air. 
  • On food preparation areas 
  • On moist surfaces 
  • Any place where pets or children can easily  

Outdoor Application

To apply DE outdoors, consider using a wet spray solution, known as slurry. 

A slurry is a mixture of DE powder and water. Using one will allow you to apply DE powder in larger areas.

While DE will not work when wet, it will work again once the solution has dried up.

To make a slurry, mix eight tablespoons of DE with two cups of water in a spray bottle.

Increase the amount of DE to ⅔ cup if your infestation is extensive.

Apply DE about once a week for a full month to achieve the best results.

Reapply DE outdoors if it rains or becomes too humid.

Finally, for the best results, I recommend using DE in conjunction with ant bait. 

3. Eliminate Food And Water Sources

Remove any food and water sources for the ants.

Doing so will help accomplish two things: eliminate ants and keep them focused on your bait.

Check for leaks or areas where moisture is building in your house and fix them.

You’ll also want to keep your floor dry. Wipe-down any wet surfaces to remove excess moisture.

Keep all open food sealed. Wipe counters and other surfaces you eat to remove any food residue.

Vacuum your floor to remove any food crumbs. Pay special attention to areas you don’t typically clean.

For instance, there may be food crumbs under your couch, bed, fridge and stove.

Ants are tiny and can thrive with the smallest amount of food. So be sure to be thorough.

4. Use Pre-Bait to Attract Ants

One way you can entice ants to walk through DE is by using Pre-Bait or ant bait.

Pre-bait is a non-toxic lure that will attract ants.

The most common and effective pre-baits are peanut butter and honey. Most ants will either consume sugar or protein. These pre-bais allow you to target

You can place the bait strategically so that ants must cross DE to reach it.

For example, if you apply DE under your appliances. You can place pre-bait at the center to attract ants.

This will cause them to walk over the DE much faster than waiting for it to happen naturally.

Pre-bait allows you to use everyday household products to enhance the effectiveness of DE.

5. Clean Up and Reapply

After you apply DE, it’s important that you clean.

You can clean DE once you feel the treatment is finished. Or you can clean after several weeks to reapply.

Cleaning is essential because it will keep DE from spreading and getting suspended in the air. If DE is inhaled, it can cause respiratory inflammation.

You can clean DE one of two ways:

  • Vacuum
  • Moping or wet cloth

When cleaning DE never use a broom. This will suspend DE in the air.


Vacuuming is the easiest and most effective way to clean DE.

Make sure you clean your vacuum frequently. Vacuuming lots of dust can clog your vacuum filter and potentially damage the engine.

I also recommend that you use a hose attachment to pick up DE.

Using rollers or larger extensions can cause dust to enter the air.

Moping or Wet Cloth

Another way you can remove DE is by using a mop or wet cloth. The water will prevent the DE from getting into the air.

This method is more time-consuming but also very effective.

Avoid fast stroking motions. This can generate wind that suspends that DE. Use slow, methodical strokes to clean the DE.

5. Keep Ants Away With Preventative Measure

We’ve all heard the maxim: prevention is better than cure. And when it comes to ants, this is undoubtedly true.

Here are some of the best tips and strategies to stop ants from invading your home:

Eliminate Food

One of the best things you can do to keep ants out of your house is cleaning up any food or water sources.

Store food properly in airtight containers or bags, including dog food.

Clean and store your pets’ food and water bowls when they are not eating.

Wipe down surfaces where you recently saw an ant trail to remove ant trail pheromones.

Clean up food preparation areas to remove any food residue and crumbs.

I also recommend cleaning underneath and behind appliances where food tends to accumulate, such as the refrigerator, microwave, and stove.

Another thing that to consider is indoor plants.

Some indoor plants are home to aphids that produce honeydew, which attracts ants. Indoor plants can also be home to small insects that ants feed on.

Eliminate Water

Ants need water to survive.

If there are no food sources, but there’s a water source, ants will still have a reason to enter your home.

This is particularly true when the soil outside is dry and needs to find additional water sources.

Make sure you address any excess moisture issues both inside and outside of your house.

This includes leaking pipes or faucets.

Standing water or overwatering of plants and grass outdoors.

Seal Up Entry Points

The harder it is for ants to get in, the less likely they will enter your home.

Tho keep ants from entering your home, seal up any cracks, holes, and crevices around your home using caulk.

Some common places to look outside are:

  • Cracks in foundation
  • Holes or cracks on walls
  • Door or Window Sills
  • Under or around windows and doors.
  • Pipes or Wires that penetrate walls.
  • Typical places to look indoors include:
  • Cracks on walls
  • Around windows and doors
  • foundation or edges walls
  • under sinks where there are pipes
  • electrical sockets

It is also good to apply DE or dust insecticide into these crevices before sealing them up.

This will allow you to kill any ants hiding inside these voids and give them no way of getting out.


How long does DE take to work on ants?

When ants get in contact with DE, they don’t die right away.

Don’t worry. That’s a good thing.

Because DE is slow-acting, it allows ants to nest and spread the DE to the rest of the population.

The powder then gets transferred to other ants and kills them as well.

It can take a few hours to a few days for DE to kill ants depending on environmental factors such as humidity, moisture content, etc.

An article on national geographic states that DE can deliver a swift death for insects within 12 hours.

Do ants take Diatomaceous Earth back to the nest?

Yes. When ants get in contact with DE, they don’t die right away.

Instead, the ants will unintentionally carry it back to their nest. The powder then gets transferred to other ants and kills them as well.

Can you use Diatomaceous Earth outdoors?

Yes. DE can work indoors as well as outdoors.

You can place DE where you can find ant trails, including walls, trees, or directly on ant mounds.

Keep in mind, DE’s effectiveness outdoors is dependent on a few factors:

  1. Exposure to wind
  2. Relative humidity 
  3. Rain

High wind blows the DE powder off, so it’s important to reapply.

Also, DE will not work when wet. So if it’s humid or raining outside, it would lose its efficacy against ants.

When applying DE outdoors, I recommend using a hand duster or power duster.

To apply DE on larger areas, consider using a slurry. 

A slurry is a wet spray solution made with a mixture of DE powder and water.

While DE will not work when wet, it will work again once the solution has dried up.

To make a slurry, mix eight tablespoons of DE with two cups of water in a spray bottle.

Increase the amount of DE to ⅔ cup if your infestation is extensive.

Apply DE about once a week for a full month to achieve the best results.

Reapply DE outdoors if it rains or becomes too humid.

Is Diatomaceous Earth safe for pets?

The short answer: Yes. DE is safe for humans and pets.

However, prolonged exposure to large quantities of DE might irritate the pets’ lungs.

You should also prevent your pet from ingesting DE.

Ingesting DE can cause minor irritation to the respiratory tract for pets.

If ingested in large amounts once or gradually, DE can cause more severe problems.

The U.S. exposure standards for DE is 6 mg/m2 of dust with less than 1% crystalline silica.

Overall, it’s best to store DE in a secure location away from your pets and children.

What are the side effects of DE?

Prolonged exposure to DE may lead to lung problems.

Thus, when dealing with DE, it’s vital that you wear a mask.

You also do not want to apply too much DE on areas where people and pets frequent.

The U.S. exposure standards for DE exposure is about 6 mg/m2 of dust with less than 1% crystalline silica,

Other negative side effects of DE are that it kills beneficial insects such as bees and moths.

DE can also inflict significant weight loss in crops.

One study showed DE application at a rate of 500 ppm caused a decrease of about 6 kg/hl in bulk density of wheat, barley, oats, rye, or corn.

Where can I get DE?

DE is available in different forms including, crushed silica, silica gel, granules, milled or micronized, and calcined. 

You can get DE by ordering online or by visiting your local agricultural feed supply stores.

When purchasing DE, make sure to use only registered U.S. Environmental Protection Agency DE for safety purposes.

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