How Diatomaceous Earth Takes on Spiders: Spider Killer

Spiders, those eight-legged intruders, can quickly turn our homes into a web-filled nightmare. But fear not! Nature has provided us with a secret weapon: diatomaceous earth. 

In this article, we unveil the remarkable power of diatomaceous earth as a natural spider killer. 

Discover how this fine powder unleashes its deadly defense, taking on spiders with its unique mechanism of action. 

Important Note: If you're tired of pests and want a reliable solution, then you should definitely consider seeking help from a professional pest control company. DIY solutions can be effective, but if you're dealing with a significant pest infestation, you don't want to rely solely on DIY methods. Pest control companies typically don't charge huge fees. You can fill out this form to receive free quotes from the top local pest control companies, and compare the quotes and see for yourself. Then, finally, your pest problems will be eliminated for good.

Say goodbye to unwanted arachnid guests and reclaim your space!

Does Diatomaceous Earth Kill Spiders

Yes, diatomaceous earth does kill spiders. Its fine particles damage the spiders’ exoskeleton, leading to dehydration and ultimately their demise. It’s a natural and effective solution for eliminating spider infestations in homes and gardens.

Does Diatomaceous Earth Kill Spiders?

How to Use Diatomaceous Earth to Get Rid Of Spiders

Choose the Right Diatomaceous Earth 

Look for food-grade diatomaceous earth, which is safe for use around humans and pets. Avoid using pool-grade diatomaceous earth, as it contains additional chemicals that may be harmful.

Identify Problem Areas 

Determine the areas where spiders are most commonly found, such as corners, cracks, crevices, and entry points. These are the areas where you should focus your diatomaceous earth application.

Prepare the Area 

Before applying diatomaceous earth, clean the targeted areas to remove dust, webs, and debris. This ensures better adherence and effectiveness of the diatomaceous earth.

Wear Protective Gear

While diatomaceous earth is generally safe, it is advisable to wear a mask and gloves when applying it to minimize inhalation and skin contact.

Apply Diatomaceous Earth 

There are a few ways to apply diatomaceous earth

Dusting Method

  • Fill a hand duster or a soft brush with diatomaceous earth.
  • Apply a thin and even layer of diatomaceous earth in the identified areas, paying attention to cracks, corners, baseboards, and other spider-hiding spots.
  • Repeat the process for all targeted areas, ensuring thorough coverage.

Spraying Method

  • Mix diatomaceous earth with water to create a spray solution according to the manufacturer’s instructions.
  • Transfer the mixture to a spray bottle.
  • Spray the solution directly onto surfaces where spiders are present, ensuring thorough coverage.
  • Allow the sprayed areas to dry completely before re-entering the space.

Barrier Application

  • Sprinkle a line or ring of diatomaceous earth around the perimeter of your home, windows, doors, or any other entry points.
  • Ensure the line or ring is continuous and uninterrupted to create an effective barrier.
  • Reapply the diatomaceous earth after heavy rain or if the barrier gets disturbed or washed away.
how to use diatomaceous earth to get rid of spiders

Safety measures when using diatomaceous earth

Wear Protective Gear

Although diatomaceous earth is generally safe, it is recommended to wear a mask and gloves when applying it to minimize inhalation and skin contact.

Avoid Windy Conditions

Apply diatomaceous earth on calm days to prevent it from being blown away, ensuring targeted application.

Keep Away from Eyes and Face 

Avoid direct contact with diatomaceous earth with the eyes, as it may cause irritation. Take caution not to inhale the powder or expose it to your face.

Follow the Manufacturer’s Instructions

Always read and follow the instructions provided by the manufacturer regarding proper application and safety guidelines.

Keep Away from Children and Pets 

While food-grade diatomaceous earth is considered safe, it is advisable to keep it out of reach of children and pets. Store it in a secure place after use.

safety measures when using diatomaceous earth

How Diatomaceous Earth Affects Spider

The abrasive nature of diatomaceous earth causes tiny cuts and scratches on the outer layer of the spiders’ exoskeleton. 

This layer acts as a protective barrier against moisture loss. Once the exoskeleton is damaged, it becomes more permeable, making it difficult for spiders to regulate their internal water balance.

The jagged edges of diatomaceous earth particles further exacerbate this damage by penetrating the soft tissues underneath the exoskeleton. 

This penetration disrupts the spiders’ physiological processes and compromises their ability to function properly and eventually leads to death.

Additional Considerations

Moisture and Humidity

Diatomaceous earth loses its effectiveness when exposed to moisture or high humidity. In humid environments, it may become damp and less abrasive, reducing its impact on spiders. Regular reapplication is necessary for such conditions.

Direct Contact Requirement

Diatomaceous earth’s effectiveness relies on spiders coming into direct contact with the powder. It may not be as effective against spiders that predominantly stay above ground or avoid areas treated with diatomaceous earth.

Time for Results

Diatomaceous earth is not an instant solution. It takes time for spiders to come into contact with the powder and for the effects to become evident. Patience and consistent application are key.

can diatomaceous earth kill all types of spiders

Frequently Asked Questions

Can diatomaceous earth be used to kill all types of spiders?

Yes, diatomaceous earth is effective against all types of spiders. This is because it targets the exoskeleton of insects and arachnids, which all spiders have. 

However, it’s important to use the product correctly and consistently for the best results. 

Shake the spray bottle vigorously until the DE is evenly distributed throughout the mixture and apply it in areas where spiders are frequently seen.

Can diatomaceous earth kill spiders in hard-to-reach places?

Yes, diatomaceous earth can kill spiders in hard-to-reach places. Its small particle size allows it to penetrate into small cracks and crevices where spiders may hide.

Sprinkle diatomaceous earth in thin layers in hard-to-reach places like cracks and corners, and around windows and baseboards.

This material will stick to the spider’s exoskeleton and eventually cause death by dehydration.

Can you mix diatomaceous earth with water to kill spiders?

Yes, you can mix diatomaceous earth with water to make a spray for killing spiders. Mix several tablespoons of diatomaceous earth with a gallon of water and shake the solution until it is well-distributed. 

Then, spray the mixture in areas where spiders are commonly found, including baseboards, windowsills, and doorways. 

When the solution dries, the diatomaceous earth particles will stick to the spider’s exoskeleton, causing death by dehydration.

How long does it take for diatomaceous earth to kill spiders?

Death does not happen on contact but over a short period of time. 

If left undisturbed, diatomaceous earth can be effective within 24 hours, though better results are usually apparent after five days. 

The effectiveness can last indefinitely as long as the diatomaceous earth remains dry.

how long does it take for diatomaceous earth to kill spiders


Diatomaceous earth proves to be a formidable natural spider killer. Its abrasive nature and moisture-absorbing properties wreak havoc on spiders, leading to their demise through dehydration. 

While it may have limitations and require regular reapplication, its effectiveness, and eco-friendly nature make it a valuable tool in spider control. 

Exploring natural remedies is a favorable choice for individuals experiencing allergies or irritation caused by certain chemicals. Cinnamon act as an effective spider-repellent and you can also try citronella to repel spider.

Implement these options and enjoy a home free from spiders.

Photo of author


Daniel White
I'm Daniel White, and I live in Jacksonville, Florida. The warm and humid climate of Florida gives an ideal habitat for many different kinds of pests. So, if I had to live in Florida, I had to learn how to deal with these pests. Now, I have 7 years of experience in Pest Control.

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