Does Diatomaceous Earth Kill Spiders? The Natural Spider Killer

Does diatomaceous earth kill spiders? This is a common question among homeowners looking for an effective and safe way to get rid of these unwanted guests. The short answer is yes, it does! But how exactly does it work, and what are the best practices for using diatomaceous earth as a spider control measure?

In this article, we’ll answer all your questions about using diatomaceous earth to kill spiders. From the time it takes to work to how often to apply it, we’ve got you covered.

Keep reading to discover how to naturally and effectively get rid of those eight-legged roommates for good.

What is Diatomaceous Earth?

Does Diatomaceous Earth Kill Spiders? what is Does Diatomaceous Earth ?

Diatomaceous earth, also known as DE, is a fine, powdery substance made up of the fossilized remains of tiny aquatic organisms called diatoms. These diatoms have a hard, silica-based shell that, when ground into a powder, forms the substance we know as diatomaceous earth.

DE is often used as a natural insecticide and pest control agent, thanks to its abrasive and desiccant properties. When insects come into contact with diatomaceous earth, the powder acts as a sort of “drying agent,” absorbing the oils and fats from their exoskeletons and causing them to dehydrate and die.

Because of its physical properties, diatomaceous earth is considered to be one of the safest and most natural ways to control pests without the use of harmful chemicals.

Diatomaceous earth is also used in a variety of other applications, such as water filtration, food preservation, and even in cosmetic products.

It is available in various grades, including food grade and industrial grade, with food grade DE being the most commonly used for pest control and other household applications.

One of the unique characteristics of diatomaceous earth is its ability to kill insects without harming larger animals or humans.

While it may be harmful to insects and other pests, it is considered to be non-toxic and safe for use around people and pets when used according to the manufacturer’s instructions.

Related Article – How Does Diatomaceous Earth Kill Spiders?

Diatomaceous earth kills spiders by dehydrating them in several different ways.

Kill Spiders Naturally With Diatomaceous (Essential Home and Garden)

First, it absorbs the oils and waxes that are present in the spider’s exoskeleton. This exoskeleton helps to retain moisture and protect the spider from dehydration. When the oils and waxes are absorbed by the diatomaceous earth, the exoskeleton becomes porous, and the spider loses water and dehydrates.

The powder sticks to the spider and clogs up its joints and breathing openings. The diatomaceous earth gets trapped in the spider’s joints, legs, spinnerets, and tracheal tube openings. This prevents the spider from moving properly and breathing normally.

It creates dry patches on the exoskeleton. When the diatomaceous earth comes in direct contact with the exoskeleton, it absorbs moisture and oils, creating dry, cracked patches. Under these patches, the spider loses water and dries out.

It damages the cuticle, which is a thin layer under the exoskeleton. When damaged, more water and fluids can escape, further reducing the spider’s ability to retain moisture.

Lastly, spiders groom themselves constantly using their mouthparts and legs. When a spider comes in contact with the powder, it will ingest and rub the powder all over its body during grooming. This results in the powder being distributed evenly under its exoskeleton, which speeds up dehydration.

Numerous studies have shown the diatomaceous earth’s effectiveness in killing spiders, making it a popular choice for those looking for a natural pest control solution.

All of these methods work by pulling moisture away from the spider and disrupting its ability to retain water. Without the ability to stay hydrated, the spider will eventually die from dehydration. 

In some cases, the clogging of key respiratory openings may also hinder oxygen intake, causing death.

How to Use Diatomaceous Earth to Kill Spiders

Using diatomaceous earth to get rid of spiders is a straightforward and effective method. By following a few simple steps, you can use this natural substance to eliminate spiders from your home or other living spaces.

However, it’s essential to take safety precautions when handling diatomaceous earth, as it can be irritating if inhaled or if it comes into contact with your eyes or skin.

Here we’ll provide you with step-by-step instructions on how to use diatomaceous earth to kill spiders, as well as some safety precautions you should take when handling this substance.

How to Kill Spiders With Diatomaceous Earth (Pests, Weeds & Problems)

Choose the right type of diatomaceous earth

The first step in using diatomaceous earth to kill spiders is to choose the right type of product. There are two main types of diatomaceous earth: food-grade and filter-grade.

Food-grade diatomaceous earth is safe for humans and animals to ingest, as it has been treated to remove impurities and any harmful crystalline silica. This type of diatomaceous earth is often used in gardens and as a natural insecticide.

Filter-grade diatomaceous earth, on the other hand, is not safe for consumption and is typically used for industrial purposes such as filtering water or chemicals. It can contain higher levels of crystalline silica, which can be harmful if inhaled.

When using diatomaceous earth to kill spiders, it is important to choose a food-grade product to ensure it is safe for use around humans and pets.

Look for a product that is specifically labeled as “food-grade” or “safe for use around pets and humans.” This will help ensure that the diatomaceous earth you are using is safe and effective for your intended purpose.

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Locate the infested areas

Before applying diatomaceous earth, you need to locate the areas where spiders are present.

Check areas where spiders tend to build webs or hide, such as corners, cracks, crevices, and dark areas. These could be places like basements, attics, crawl spaces, closets, and storage areas. Make sure to wear gloves and use a flashlight to avoid any surprises.

Apply the diatomaceous earth

Applying diatomaceous earth is a simple process that can be done by anyone. After choosing the right type of diatomaceous earth and locating the infested areas, it’s time to apply the powder.

To apply diatomaceous earth, put on protective gloves and a dust mask to avoid inhaling the fine powder. Then, take a small amount of the powder and sprinkle it in the affected areas, making sure to cover all the cracks, crevices, and corners where spiders may hide.

You can use a duster or a paintbrush to spread the powder evenly, or simply sprinkle it by hand. Be sure to apply a thin layer of the powder, as a thick layer may not be as effective.

It’s essential to apply the powder in dry conditions as moisture will make it clump together and lose its effectiveness. Also, avoid using diatomaceous earth in areas with high foot traffic, as it can be easily disturbed and lose its effectiveness.

After applying the diatomaceous earth, leave it for a few days to allow it to take effect. Remember to reapply the powder if it gets wet or if you notice spiders returning to the treated areas.

Reapply as needed

Reapplying diatomaceous earth as needed is an important step in controlling spider infestations. Spiders can continue to enter your home, and any new spiders that come into contact with the diatomaceous earth will also be affected by it.

You should reapply the diatomaceous earth every two to three weeks, especially in areas where it may have been disturbed or cleaned up. It’s also a good idea to reapply after any heavy rain or damp weather, as the moisture can render the diatomaceous earth less effective.

If you notice that the number of spiders in your home has not decreased after a few weeks of applying diatomaceous earth, it may be necessary to increase the amount or frequency of application.

Remember to always follow the instructions on the packaging and take proper safety precautions when handling diatomaceous earth.

Vacuum up the dead spiders

After the diatomaceous earth has had time to work its magic, you can start vacuuming up the dead spiders.

Use a vacuum cleaner with a hose attachment to carefully remove the spider carcasses and any remaining diatomaceous earth. Dispose of the contents of the vacuum bag in a sealed trash bag and discard it outside of your home.

It’s important to note that diatomaceous earth can clog vacuum filters and cause damage to vacuum cleaners, so it’s recommended to use a vacuum specifically designed for cleaning up fine powders.

Alternatively, you can use a broom and dustpan to sweep up the diatomaceous earth and spider remains, but be sure to wear a mask to avoid inhaling any fine dust particles.

By following these simple steps, you can effectively use diatomaceous earth to eliminate spiders from your home.

How To Use Diatomaceous Earth For Spiders On Carpet

Does Diatomaceous Earth Kill Spiders How To Use Diatomaceous Earth For Spiders On Carpet

If you have spiders on your carpet and want to use diatomaceous earth to get rid of them, here’s how to do it:

  • Vacuum the carpet thoroughly to remove any loose dirt and dust.
  • Sprinkle a light layer of diatomaceous earth onto the carpet. Use a dust mask to avoid inhaling the powder and make sure to cover your skin, as DE can dry it out.
  • Use a soft brush or broom to work the powder into the carpet fibers.
  • Leave the diatomaceous earth on the carpet for at least 4 hours or overnight.
  • Vacuum the carpet again to remove the dead spiders and any remaining DE.
It's important to note that you should only use food-grade diatomaceous earth on carpets and avoid getting it wet, as it will lose its effectiveness. 

Safety Precautions To Take When Using Diatomaceous Earth

Wear protective gear: Diatomaceous earth can be irritating to the skin, eyes, and lungs, so it’s important to wear gloves, a mask, and safety goggles when handling the powder.

Keep it away from children and pets: Diatomaceous earth is not toxic, but it can still be harmful if ingested or inhaled in large amounts. Keep the powder out of reach of children and pets.

Use it in well-ventilated areas: To avoid inhaling the powder, use it in well-ventilated areas or wear a mask.

Avoid getting it wet: Diatomaceous earth loses its effectiveness when it gets wet, so it’s important to keep it dry. If it does get wet, you will need to reapply it.

Don’t use too much: Using too much diatomaceous earth can create a mess and make it less effective. Use only as much as necessary to cover the infested areas.

Follow the instructions carefully: Be sure to read and follow the instructions on the packaging carefully to ensure the safe and effective use of diatomaceous earth.

Using diatomaceous earth to kill spiders is an effective and safe method, as long as proper precautions are taken. 

Remember to choose the right type of diatomaceous earth, locate the infested areas, apply the powder carefully, and vacuum up the dead spiders.

Always wear a mask and gloves when handling diatomaceous earth and keep it away from children and pets. 

By following these simple steps, you can get rid of spiders in your home without using harmful chemicals.
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How Long Does Diatomaceous Earth Take to Kill Spiders?

The amount of time it takes can vary depending on a few different factors. In general, it can take anywhere from several hours to several days for diatomaceous earth to kill spiders.

One factor that can affect the speed of the process is the type of spider. Some species may be more resistant to the effects of diatomaceous earth than others. Additionally, the size of the spider can also play a role. Larger spiders may take longer to succumb to the effects of diatomaceous earth.

The amount of diatomaceous earth used and the manner in which it is applied can also impact the speed of the process.

A thicker layer of diatomaceous earth may be more effective at killing spiders, but it may take longer for the spiders to come into contact with it.

Finally, environmental factors can also play a role. Higher humidity and moisture can cause diatomaceous earth to clump, making it less effective at killing spiders. In drier conditions, diatomaceous earth may work more quickly.

So while diatomaceous earth can be an effective way to kill spiders, the amount of time it takes can vary depending on the type of spider, the amount and application of diatomaceous earth, and environmental factors. 

It is important to be patient and allow enough time for the process to work.

Will Diatomaceous Earth Stick to Spider Webs?

Diatomaceous earth can stick to spider webs if it is applied directly to the web or in areas where the web is located. However, it may not be as effective in killing spiders that are already living in the webs.

Does Diatomaceous Earth Kill Spiders? Will Diatomaceous Earth Stick to Spider Webs?

Using diatomaceous earth in areas with spider webs can have both pros and cons. On the one hand, it can help kill spiders and prevent them from returning to the webs.

Related Article – What Happens When You Destroy Spider Webs?

On the other hand, it can also make the webs less visible and potentially damage them if too much diatomaceous earth is applied.

If you decide to use diatomaceous earth in areas with spider webs, it is recommended to apply it lightly and avoid direct contact with the webs themselves.

This can help minimize any potential damage and still effectively control spider infestations. However, if spider webs are present in high-traffic areas of your home or business, it may be best to consider other pest control methods to avoid any potential hazards.

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Does Diatomaceous Earth Keep Spiders Away?

As we already explained, diatomaceous earth is a great way to kill spiders. But does it have repellent properties? The answer is yes, diatomaceous earth can keep spiders away. However, it’s important to keep your home clean in the first place to prevent spiders from coming inside.

Apart from using diatomaceous earth, there are other measures that you can take to keep spiders away.

First, make sure that there are no entry points for spiders to come into your home. This means sealing any cracks or gaps in doors, windows, and walls.

You can also use essential oils such as peppermint, tea tree, or citrus to repel spiders. Simply mix a few drops of the oil with water and spray it around your home.

Another effective way to keep spiders away is to eliminate their food source. Spiders usually come inside looking for prey such as other insects.

Therefore, it’s important to keep your home clean and free of crumbs, food debris, and other organic matter that can attract insects. Vacuuming your home regularly can also help eliminate spiders and their food source.

Diatomaceous earth can keep spiders away but it's important to combine it with other measures such as keeping your home clean and free of entry points.

Using essential oils and eliminating spiders' food source can also help keep spiders away from your home.

Why Do Exterminators Not Use Diatomaceous Earth?

Exterminators are professionals who are trained to handle pest infestations. While diatomaceous earth (DE) is a popular choice for homeowners to deal with spiders and other insects, some exterminators may not use it as their go-to method of pest control.

One reason for this could be the limitations of DE as an insecticide. While it is effective in killing insects with an exoskeleton, it may not work as well on pests that have a soft bodies, such as bed bugs. In addition, DE may not be effective against all species of spiders, as some may be resistant to its effects.

Another factor is that DE may not be the most efficient method of pest control in all situations. Exterminators may prefer to use other methods, such as chemical sprays or bait traps, that can be more effective in certain circumstances.

Why You May Not Want to Use DA for pest control (Slightly Rednecked)

However, it is worth noting that some exterminators do use diatomaceous earth as part of their pest control strategy, particularly in situations where chemical sprays may not be appropriate, such as in homes with children or pets.

Ultimately, the choice of pest control method depends on the specific situation and the preferences of the exterminator.

While diatomaceous earth can be a useful tool for homeowners in dealing with spider infestations, its limitations as an insecticide may make it less appealing to some professional exterminators. 

Nonetheless, DE can still be a valuable option for home use and can be an effective part of an integrated pest management strategy.

Final Thoughts

If you are struggling with a spider infestation in your home, diatomaceous earth may be the natural solution you’ve been looking for. Not only is it safe and effective, but it is also affordable and environmentally friendly.

By following the simple steps outlined in this article, you can use diatomaceous earth to eliminate spiders and other pests from your home for good. it is important to follow safety precautions when using it and to understand its limitations as an insecticide.

If you are looking for a natural way to control spider infestations, diatomaceous earth can be a great choice. So why not give it a try and see the results for yourself?


Does food-grade diatomaceous earth kill spiders?

Yes, food-grade diatomaceous earth can effectively kill spiders and other pests.

What time of day should I apply diatomaceous earth?

It is best to apply diatomaceous earth in the morning or evening when spiders and other pests are most active.

How often should I sprinkle diatomaceous earth?

This depends on the severity of the infestation. In general, it is recommended to apply diatomaceous earth once a week or as needed.

Does diatomaceous earth kill black widow spiders?

Yes, diatomaceous earth can effectively kill black widow spiders.

Does diatomaceous earth kill brown recluse spiders?

Yes, diatomaceous earth can kill brown recluse spiders.

Is diatomaceous earth safe for jumping spiders?

No, diatomaceous earth is not safe for jumping spiders as it can kill them.

Does diatomaceous earth work better for spiders than chemical insecticides?

Diatomaceous earth is an effective alternative to chemical insecticides for killing spiders and other pests. It is non-toxic and safe to use around children and pets and does not harm the environment. Additionally, insects and spiders cannot develop a resistance to diatomaceous earth, so it remains an effective solution over time.

Resources – (for further reading)

Oregon State University – Diatomaceous Earth General Fact Sheet

Springer – Strains in the exoskeleton of spiders

National Library of Medicine – Diatomaceous Earth for Arthropod Pest Control

I'm Ernest M Noah, the founder of I have years of experience as an exterminator in Texas and Idaho, and I'm passionate about educating people on how to deal with pest problems effectively and safely.