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What is the Best Natural Fire Ant Killer?

What is the Best Natural Fire Ant Killer?

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Paul Brown

Chances are, if you are researching “natural insecticides for fire ants,” you are looking for a non or less-toxic substance or procedure to rid your yard of these pests. Several less-toxic remedies exist, but many home remedies will not work.

For a less-toxic fire ant treatment, using a fire ant bait coupled with boiling water “mound drenches” will significantly minimize the risk of polluting the surrounding environment. 

Knowing your yard’s environment (animals, soil composition, plant growth, etc.) will help you assess your safety needs.

 There may be cases where synthetic insecticides would do less damage than a certified “natural option.” 

What is a Natural Insecticide?

A google search of “natural insecticides” will likely bring up a list of wives’ tales, as people tend to think “home remedies” or “harmless” when using the word “natural.” 

Despite this cultural perpetuation, “natural” does not inherently mean “harmless,” “chemical-free,” or “homemade.” According to PennState (source), insecticides will mostly fall under one of the following categories:

  • Chemical insecticide: Not always as harmful as it sounds – water is a chemical
  • Synthetic insecticide: Not found in nature, does not contain carbon
  • Organic insecticide: Only defining factor is that it contains carbon – technically, DDT is organic
  • Natural insecticide: Made in nature, but not necessarily harmless – nature creates some harmful substances.  Natural does not exclusively mean non-toxic, and it does not mean it is free of additives

When searching for an insecticide, remember that the certified definitions of these categories may not match the common-knowledge definitions.  You will find bottled, manufactured insecticides under all of these labels.

Regardless, no method will work unless you know what you are targeting and when to target it.

The Fire Ant Colony

To know which methods would most effectively and safely control a fire ant population, it is important to know the nature of what you are targeting. 

Fire ant mounds are known by their dome shape and their lack of an opening on top.  Fire ants burrow deep in the ground and create mazes of tunnels that lead up to the surface surrounding the mound.

The queen is safely tucked away at the heart of the colony, where she continuously produces worker ants (NC State: Homegrown).

The ants tasked with food scavenging will bring food back to the colony and pass it to the queen through regurgitation (Queensland Government).

They typically scavenge when the weather is between 72-96 degrees Fahrenheit ( and will burrow deep in the ground when it is cold.

Basically, the queen determines whether the colony survives or not.  As long as the queen lives, the colony will probably grow back, even if it is damaged. 

This is why successful extermination methods target her food source and the depth of the colony where she resides.

Fire Ant Extermination: The Basics

To effectively exterminate a fire ant colony, you want to kill the queen ant and her successors.  According to the Mississippi State University Extension, fire ant control comes in two main forms: baits and mound drenches (source).

  • Bait: Active, slow-working toxins are injected in the bait.  Worker ants pass the food down the line to the queen.  Sometimes these ingredients directly kill the queen; other times, it stunts her reproduction (see which fire ant bait should I use). Bait requires very small amounts of toxins and should not damage the ground.
  • Generally, baits will not work if placed on top of the mound because there are no openings there; they should be placed surrounding the mound.  They will also not work if they are set when the ants would not be out scavenging (IE: setting bait on cold days will not work). 
  • Mound drenches: Usually, a chemical mixed with water poured directly on the mound.  These work quickly if there is enough liquid to drench all the way down to the queen, but they may do more damage to the surrounding area.
  • Mound drenches are effective if they reach the queen, which is why it is important to follow the correct dosage given on these options.

For small land plots like yards, Mississippi State University suggests combining these methods.  Begin with baiting as the main treatment.  These should be set in the appropriate temperature when ants are out foraging and when you do not expect rain for a few days. 

Allow a few days for the bait to make it through the colony and down to queen, where the slow-acting poison should still be viable. This should start eliminating the mound from the inside out. 

From this point, mound drenches should be used to target individual mounds as they try to grow back. 

Home Remedies

Most homemade remedies are ineffective if they are not properly researched.  Several are actually more harmful to the environment than a manufactured insecticide.

According to Texas Agrilife Extension, home remedies that should not be used on their own include:

  • Gasoline
  • Summer oils
  • Soaps

These can all pose a threat to the environment.  There are organic insecticides that use some of these products, but many are topical plant treatments that would not work on fire ants.

Other home remedies for fire ant control that prove little to no effectiveness include: molasses, coffee grounds, baking soda, cinnamon, and garlic.

However, one home remedy that receives consistent positive feedback is boiling waterThis would be used as a mound drench and would not add any toxins to the environment.  If it can be administered safely to avoid burns, 3 gallons of boiling water per mound is effective in killing up to 60% of the mound. 

What is the Best Less-Toxic Home Treatment?

The besttreatment for fire ants in your yard is to combine baits and mound drenches. Baits will target the food source for a systemic attack, and following with the mound drenches will target individual mounds as they regenerate at smaller capacities.

Fortunately, baits are simple products with few ingredients, two of which are plant-based.  Most baits will contain:

  • The active toxin
  • Soybean oil
  • Corn-based carrier

These will do little damage (if any) to the environment and most other animals, since only small amounts of the toxin is required.  These are two of the best ant baits (links to Amazon):

For mound drenching, the least toxic option is boiling water.  This could kill the surrounding grass, but it will not add toxins to the ground. 

In terms of products, d-limonene is a citrus peel extract that is present in mound drenches that are labeled as “organic” or “natural.” Orange Guard (link to Amazon) is a common mound drench ingredient.

When looking for natural fire ant killers, remember that labeling something as “natural” does not always mean it is less toxic than other options, including synthetic products. 

To find the safest treatment, you need to start with understanding what the treatment is targeting (in this case, the queen ant).  From here, you can choose whether to use certified “natural” treatments, less-toxic options, or whatever fits your needs best

Related Reading: Ants In Clay Soil – Why You May Not Want To Kill Them