Does Diatomaceous Earth Kill Ants? Can it Help Prevent Them?

In this article, we will educate you on all things diatomaceous earth and using it for ants. Answering all the relevant questions that you need answers to, such as what is it, how it works, and whether it kills ants effectively, and much more.

There are few better killjoys than ants. Those pesky little critters that appear out of nowhere and engulf you and the alfresco food you’re trying to enjoy in your backyard.

Ants have a reputation for being great workers. Their work ethic is relentless, continually on the lookout for food, and they seem impossible to evict. That is until now.

So let’s get down and dirty with the DE 101.

What is Diatomaceous Earth?

Diatomaceous earth (dia-tom-aysh-us earth) comprises of aquatic organisms called diatoms. These tiny fossilized remains are made of a substance called silica. Silica is naturally occurring and found in many living organisms, as well as making up 26% of the earth’s crust.

Throughout time all the dead diatoms have accumulated in the sediment of water bodies such as streams, lakes, and oceans.

Man has learned to mine these areas when they dry out to extract the silica in the form of DE.

This natural substance has many applications that can assist in food production for both human consumption or otherwise. It is also used as a mechanical processor to aid filtration, a stabilizer for dynamite, and as a soil for potted plants and trees like Bonsai.

Does it Kill or Prevent Ants?

In short, you bet it does. It’s a natural product, so if you’re keen to avoid chemical ant killers, this is one of the best solutions for you.

As it goes, DE is both inexpensive and effective in destroying ants, earwigs, slugs, beetles, ticks, fleas, cockroaches, and bed bugs.

So it’s not only great for killing ants, but as an insect killer overall. Although how effective it is for each insect depends on their size and resilience.

But the common factor among them all is their exoskeleton. And it is their exoskeleton where it’s most effective in the treatment of ants.

How Does Diatomaceous Earth Kill Ants?

Diatomaceous earth, unlike other chemical ant killers, does not need to be eaten to solve an ant problem. In fact, it isn’t poisonous at all.

Some applications are for digestive purposes, such as a digestive aid, or to promote healthy hair and nails. But it has to be food-grade, though, so don’t go eating garden DE, please.

The short answer to how it works is quite simple – it dries them out. It’s a little like pouring salt on a slug. The lengthier, more scientific explanation is that it has microscopic sharp and abrasive edges with physico-sorptive properties.

This means it will puncture and break down the hard exoskeleton of many insects and absorb the lipids. Lipids are the oily barrier that stops the loss of body liquid, preventing them from becoming dehydrated.

The evaporation of moisture from the ant’s body is accelerated and becomes fatal by removing this layer. The ants then walk it back to their mates back at the nest and assist you in your job of killing them.

Although it sounds somewhat gruesome, the good news is, it works. Horah! Plus, it is a non-biological process, meaning ants cannot build up tolerance or immunity to it.

How Long Does it Take to Kill Ants?

On average, and in dry conditions, the general rule of thumb is that it will affect and eradicate ants within 48 to 72 hours.

Once they have made full contact with it, red ants will die in around 16 hours, and the hardier black ant will die within 24 hours.

Once the it’s been spread, and the ants come into contact with it, the result is a given. They will spread it around among the colony while they work, and it will take effect and send them off to ant heaven.

If you notice that the ants are still active after 72 hours, revisit the areas of ant traffic and reapply. You need to be persistent with it to take full effect, but trust us, it will work.

How Effective is it?

DE is great for ant control. However, it is most effective when it’s dry and the humidity is low. This keeps the particles crystalline and sharp, ensuring that it will scratch and pierce their exoskeleton faster and deeper.

Factors that will affect the length of time it takes to do the job include rain, moisture on the ground, and humidity.

If it has become wet or moist because of rain or damp soil, but it hasn’t washed away, just let it dry out. After drying, it will work again just as well.

Temperature and humidity will also influence its efficiency. The warmer and more humid it is, the less effective it will be, simply because the edges of the tiny particles soften.

Related: Vinegar as an effective ant repellant.

Is it Pet Safe and Kid Safe?

One of the deciding factors for most homeowners when it comes to pest killers is whether it is safe for children and pets.

Young children are especially vulnerable to strong chemicals because of their sensitive skin. As such, they present a much higher risk of harm if they come into contact with traditional human-made pesticides compared to adults.

Thankfully, it’s is proven to be non-toxic to both children and animals alike. So, whether it is rubbed on to the skin or ingested, it is unlikely to do any harm.

Related: The best pet safe store-bought ant killers

If breathed in as a powdered form, it can cause minor irritation to the throat and lungs. But no more so than if a child breathes in a dust cloud, or when sand blows into their face at the beach.

The same can be said for Fido and his other furry friends. Extensive testing over the years on chickens, rats, and aquatic life shows that it is pet-safe.

Chickens are regularly fed a diet that contains DE to aid the cleansing of the digestive tract. It is also placed into coops as a dust bath to rid them of ticks and mites externally without any adverse effects.

Is it Biologically & Ecologically Friendly?

Silicon is a major element in soil, rocks, sands, and clays, as well as being present in many plants. It is a key component of plant growth.

This means that many flora and fauna encounter it in their daily life through both diet and contact.

Many agencies have stated that diatomaceous earth is unlikely to affect birds, fish, or other wildlife in a harmful way.

We know that you, as an environmentally aware reader, have significant concerns surrounding human-made chemicals. Our daily use of these in our lives can mean they end up in rivers, lakes, and oceans. The negative effect this can have on aquatic life is immense. But luckily, it’s non-toxic in water as well.

The ocean contains naturally occurring DE in large quantities; after all, it is a type of phytoplankton. It is a crucial component for many marine organisms who need it for their skeletal development. So, rest assured that it is non-toxic to fish and aquatic invertebrates too.

Is it for Indoor or Outdoor Use (or Both?)

Diatomaceous earth can be applied pretty much anywhere that you find ants. Which means both indoor and outdoor use is perfectly safe. So, whether you have ants closing ranks on your prize cabbages or have an in-house pantry breach, it can be relied upon to do the job.

Unlike bicarbonate of soda that must be mixed with sugar for the ants to digest, all they have to do here is walk through it.

Outside, spreading the powder as a border around your property can be a proactive method that stops them from migrating indoors. Just apply it to any cracks in walls or foundations, and it’s as easy as that to keep them out.

There is one caveat to outdoor use, and as you already know, it’s moisture. As we said before, it needs to be dry to take full effect, so if you’re expecting a downpour, save the application for another day.

Once the ants are gone, you can clean up with a mop and bucket. Not only is this the easiest clean-up method, but it washes away any pheromones, preventing ants seeking out their wounded brethren. 

How to Use Diatomaceous Earth to Kill Ants

1. Start by locating where the ants have been congregating and then follow their entry and exit points to get a good understanding of where they are coming from. If you can follow them back to the nest, this is a bonus.
2. Spread a thin line around the main areas that the ants have been active in. Make sure to apply extra along your skirtings and windowsills where they often have multiple entry and exit points.
3. When the congregation is traveling in formation, get dusting. Applying it directly to a troop of ants is the quickest and most effective way of using DE. The ants will take it straight back to HQ and share it around. They’re selfless like that.
4. Give it a day or two to see if the ants have survived the first onslaught. If so, reapply it as needed.
5. Given the cheap nature of DE sold in bulk, please don’t be stingy with its application. This is cost-effective pest control, so it’s best just to get it done the first time. It can be used proactively to prevent an infestation, so apply it liberally around your house and the prized petunias. If you’ve got an infestation and know where the nest it, make it rain diatomaceous earth!
6. Once the battle is over and the war is won, clean it up. A good wash down of all surfaces with a hose or mop and bucket will do the trick. This will prevent the ants from returning and make your home and garden presentable once again.

Wrap Up

Well, there you have it, a cost-effective and proven solution to all your pesky insect needs – especially the eradication of ants.

And unlike other pest control solutions, you don’t need to keep Fido and the kids out of the way. But not with diatomaceous earth, it’s super easy and convenient. It is a great all-around ant killer that almost immediately takes effect, and it is biologically safe.

So, next time you find a few extra mouths to feed at the garden table, reach for the DE, and send them packing.