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What The Heck Is Diatomaceous Earth?

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What The Heck Is Diatomaceous Earth?

Diatomaceous earth (sometimes to referred to simply as DE) is one of those handy substances that has all kinds of uses around the home and garden. It is mainly used for pest control, effective at killing everything from fleas and roaches indoors to aphids and slugs outdoors.

What is Diatomaceous Earth?
It’s useful, but what the heck is it, exactly? The short answer is fossils! Diatomaceous earth (be sure to use “food grade”) is ground fossilized remains of a type of phytoplankton called diatoms, which have existed on earth for millions of years. Of course, to look at diatomaceous earth, it doesn’t look like fossils — it is more of an off-white powder that looks similar to talc and has no odor. In order to see the fossilized diatoms, one must put DE under a microscope. If you are wondering what the fossilized diatoms look like, they generally come in two shapes. The long stick-shaped diatoms are called pennates, and the round, cylindrical diatoms are centric diatoms.

How Does Diatomaceous Earth Work?
The reason why diatomaceous earth is recommended for killing bugs, is pretty simple. The dust is scratchy, so when critters with exoskeletons (hard shells on the outside) are exposed to diatomaceous earth, it cuts through that protective layer and the bugs eventually dehydrate and die. That scratchiness, caused by the microscopic edges of the fossilized diatoms, is also why diatomaceous earth irritates the skin and eyes. It is recommended that you wear a mask of you are applying it in large amounts.

We don’t normally think of fossils as being useful to have around the house, even if they are interesting. In the case of diatomaceous earth, however, a small bag can work wonders on pest problems around the home!

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Note: Diatomaceous earth will do harm to all insects with exoskeletons, even the beneficial ones in your garden, so be extra cautious when applying.

How To Use Diatomaceous Earth To Treat Fleas
Diatomaceous earth has been used for years as an insecticide to control fleas.

Step 1: Be sure the  areas you are treating are completely dry, and that the room is well ventilated and free of family or pets during the treatment process.

Step 2: Dust the affected areas (pet beds, blankets, surfaces of cat condos, etc.) with the diatomaceous earth using an applicator, or sock filled with the product.

Step 3: Let the DE penetrate the areas for an hour or more (if possible) then vacuum it up. Vacuum daily for maximum flea control.  Treat small areas at a time as you will be vacuuming up the DE and you don’t want to burn out your vacuum’s motor. Shop vacuums work well.

While DE is considered non-toxic to humans and animals; it can be drying to skin, as well as irritate eyes and nasal passages. Please talk to your veterinarian about whether DE is right for treating your pet’s skin and fur.

How To Use Diatomaceous Earth To Treat Roaches
Courtesy of

Step 1: Give your home a thorough cleaning. Sweep, mop, put away food, and vacuum thoroughly. Maintaining cleanliness is usually the best defense against cockroaches.

Step 2: Dry up any damp areas to prepare for your diatomaceous earth application. Any kind of entrance for a cockroach should be sealed up with caulk.

Step 3: Apply DE anywhere you have seen cockroaches, including around the house along the foundation. Dust lightly, since cockroaches won’t step on diatomaceous earth if the dusting is too heavy. Apply DE anywhere cockroaches can hide, enter your home, and where food is commonly dropped. Don’t apply DE to any area that is consistently damp or wet, since wet diatomaceous earth will not kill insects.

Step 4: Leave DE applied as long as the cockroach infestation continues. Reapply if the DE gets washed away. Once the cockroaches are gone, you can vacuum up the diatomaceous earth but you can also leave it down as a preventative measure against future infestations.

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1 yzoldowl { 07.30.17 at 1:30 pm }

Sam Marshall: pool-grade DE is usually treated with another chemical. Not recommended for other uses! You can get a 40-pound bag of “feed grade” DE at your local feed store; it’s the same as “food grade” and will last just short of forever.

2 Loretta Hoyland { 07.26.17 at 7:54 pm }

Will this kill squash bugs too? And keep them away too?

3 POLLY { 07.26.17 at 2:20 pm }

You said to get some at Home Depot or Lowes. Can you get this at Menards? Is the name of it DE? and what does the package look like? Very interested. Have this little beetle coming into my house. A dark brown, shaped like a diamond, and has a hard shell. Thanks

4 Chris Marcellus { 07.26.17 at 2:09 pm }

Food grade DE is a purer version of DE (very little dirt, etc…). Using non-food grade will not have near the effect food grade will, so yes there is a big difference. Putting food grade DE in your pets food will help with their coat & skin, humans can use it too – I’ve been taking about a teaspoon every morning for the last 4 years (in some water – it has a very slight neutral earthy taste). It has done wonders for my hair & nails (won’t regenerate hair like Rogaine, just help what you already have). As far as an intestinal cleanse, I’ve read one article about it “scrubbing” your intestinal walls, so I use it for the hair/nail/skin benefits. It’s full of silica, which is the beneficial ingredient for humans & pets. Most feed stores will have it.

5 Tony { 07.26.17 at 12:56 pm }

Been using this for decades and very very inexpensive.. years after it remains after many vacuums.. living in nyc no one would believe me.. as a kid I used to take care of the pool filter and this was one ingredient I had to use

6 { 07.26.17 at 12:31 pm }

do people use food grade de to cleanse their intestines. I heard they use a
teaspoon with 8 oz water. per day.


7 Sam Marshall { 07.26.17 at 12:15 pm }

Great article! What is the difference in” food grade” DE vs. the DE that I use in my pool filter? I am wondering if I can use the pool filter DE for an ant problem that I have outside? Do they work the same way? Thank you.

8 judy { 07.26.17 at 11:52 am }

Best stuff EVER!!!!!

9 L Petrie { 07.26.17 at 11:37 am }

DE is sold in most garden supply stores like D&B Supply out west and Home Depot or Lowes garden centers.

10 Carol { 07.26.17 at 11:34 am }

Where can i purchase this for my garden please de

11 Where is it sold or how do I purchase it { 07.26.17 at 10:02 am }
12 Christie Wight { 07.26.17 at 9:40 am }

DE is amazing. Good reminder for garden, tho it will work with both good and bad bugs. Recommended for bedbugs too.

I had a weird even in my apt last winter. Bugs bothering me but not my cat! Resolved the little creeps with DE. Ants will not cross it, put around foundation of house each spring. Washes into soil which gives trace minus to soil too!

I have also taken internally for parasite suspicion. Tough winter! I’m better now 🙂

13 Susan Higgins { 07.26.17 at 8:59 am }

Hi MaryJane, yes, we hear of many people using it that way with great success. We only recommend people check with their vets first. But thank you for sharing your story and we’re glad your pets are doing great!

14 MaryJane Rissberger { 07.26.17 at 6:24 am }

I use it in my cat’s kibble. I put the kibble in a large (gallon) sized canister with 1 tablespoon of the clay, shake the canister to distribute it evenly and then scoop out the daily kibble. My kitty had soft moist stool that are very stinky and this treatment has corrected that issue. The stool is less smelly and slightly firmer. My daughter and I had a kitten that was taking a much larger amount twice daily to treat diarrhea from an intestinal paracite and it helped the kitty recover and now he’s in excellent health.

15 Ree Enlow { 07.24.17 at 3:18 pm }

We love DE. Have been using it for years…it works without all the chemical smells, etc since I have allergies and asthma.

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