How To Kill Black Ants

This post may contain affiliate links so I earn a commission.

If you’re wondering how to kill black ants, you might feel as though all of your best efforts to do so have been in vain.

These little critters can be frustrating!

Unfortunately, if you’re not persistent, they’ll keep returning again and again, driving you mad as they continue to search for food.

Here are some tips on preventing and killing black ants - and regaining your sanity in the process.

What Are Black Ants?

If you’re seeing black ants in your house, chances are they are the species often referred to as “little black ants,” or Monomorium minimum.

These insect pests are tiny, with the workers as little as 1.5 millimeters in length.

Queens are larger, but not by much.

True to their name, these ants are dark brown or black in color, with 12-segmented antennae and two-segmented waists.

They are found in the United States, southern portions of Canada, and most parts of Mexico.

These ants often nest in masonry and woodwork along with yard debris and the soil.

Occasionally, however, they come inside, and that is when they become frustrating to deal with.

Little black ants do have stingers, but they aren’t large enough to pose a threat to humans.

However, if you notice these ants inside your house, that’s generally a sign that an outdoor infestation has grown relatively large and it needs to be addressed.

How To Kill Black Ants

There are several ways you can kill black ants.

Here are some of the best:

How To Kill Black Ants Using A Commercial Bait

Ant baits are easy, effective solutions you can use to kill ants and prevent them from coming back into your house.

A commercial ant bait, which is a combination of poison and a sweet substance, will attract ants and then kill them.

However, it doesn’t work immediately.

Instead, ants will eat a small amount of bait and bring the rest back to the nest so that the rest of the colony is exposed to the poison.

TERRO T300B Liquid Ant Killer

It takes some time for commercial ant bait to work, but it’s effective.

If you decide to use ant bait, make sure you place the bait in an ideal location.

Follow the instructions on the package and when possible, put the bait in front of an ant trail.

Wait a few days and make sure your house stays clean in the meantime to prevent attracting additional ants.

How To Kill Black Ants By Spraying With A Pesticide

You can also spray with a pesticide, though this of course is the least desirable option for people with pets or small children.

These chemicals are highly effective against ants, but can also cause sickness if you come into direct contact with them.

Ortho Home Defense Insect Killer

One of my favorite sprays to use is Ortho Home Defense. 

It’s simple to apply with its automatic sprayer and you can use it indoors and outdoors. 

It provides a long lasting barrier of protection that works for weeks to kill black ants as they crawl across it.

How To Kill Black Ants With Diatomaceous Earth

If you’d rather not use a chemical or a poison to get rid of ants, you can also give diatomaceous earth a try.

This all-natural substance is completely safe for use around pets and humans but works well when it comes to killing ants and other pests.

Diatomaceous Earth Food Grade

It is made of ground-up, fossilized organisms that dig into the exoskeletons of insects like ants when they walk across it.

You can sprinkle diatomaceous earth anywhere you often see ants.

You’ll need to replace the powder once or twice a week or whenever it becomes wet.

How To Kill Black Ants Using Cornstarch

If you have carpets, black ants are a nuisance even when they’re dead, since they leave behind an unpalatable-looking stain.

You can get rid of it by sprinkling your carpets with a fine layer of baking soda and cornstarch.

Let the mixture sit for a few hours then vacuum it up.

The baking soda will clean the area while the cornstarch will suffocate the ants.

Use Essential Oils To Repel Black Ants

There are some types of essential oils that ants are not particularly fond of.

Whip up a batch of essential oil ant repellants by including 10-15 drops of essential oils in a cup of water.

Some good options include peppermint, lavender, lemon, tea tree oil, and eucalyptus oil.

Cinnamon is another natural remedy that’s effective at getting rid of ants without exposing you and your family to potentially harmful chemicals.

How To Kill Black Ants With Borax

Borax, or boric acid, is another common household item that can be used in the seemingly never-ending fight against black ants.

All you need to do is sprinkle a bit of this common laundry product around room perimeters and in the corners.

Ants and other unwanted pests should die immediately after crawling over it.

You can also make a homemade ant trap by adding taking 1 cup of water, 1 cup of sugar and 2 tablespoons of borax.

Heat up the mixture so everything is dissolved and then let it cool.

You’re basically creating your own commercial ant bait

To use the bait, just pour some into a pop bottle cap or soak some cotton balls in the bait and place them throughout your home

They’re simple to make and they work amazing!

How To Kill Black Ants - Overall Prevention

There are a few things you should do when little black ants come indoors.

After you’ve killed them, you need to take steps to ensure that they do not come back.

Most of the time, little black ants come inside in search of food or water.

Because of this, you will need to eliminate any source of food.

These pests eat things like sweets, vegetables, plant secretions, greasy or oily foods, corn meal, and certain bugs, like cotton flea hoppers and other insects.

Don’t leave food out for any more than a few minutes.

Ants will sense that it is there and come to get it.

Make sure your food is tightly packaged, especially food like juice, maple syrup, crackers, and fruits with thin skin, like strawberries.

All of these are favorite foods for most ants!

After figuring out where they are finding their food, you should work to get rid of their access to it.

Seal up any food containers and clean up spills promptly.

Inspect the exterior of your home to determine if there are any cracks and gaps through which ants might be coming in.

You may also need to replace areas of dead or decaying wood, since this often attracts black ants, too.

Once you’ve killed the black ants in your home and taken steps to prevent new ones from getting inside, sit back and relax.

While you will still need to remain vigilant by cleaning up messes and keeping things tidy in the future, you can now consider your black ant problem fully behind you!