Kitchen herb may help fight one of the world's most invasive ants

Fire ants continue spreading into new areas, leaving many communities exhausted by the ongoing battle. People are looking for solutions that won’t harm their soil, pets, or gardens.

The search for solutions has taken researchers in an unexpected direction. A familiar kitchen herb may help slow one of the most stubborn invasive insects in the United States.

The rise of fire ants

Fire ants entered the country through the port of Mobile in the early 20th century and spread fast. Fields, yards and pastures still show their impact. Farmers lose crops.

Children step on hidden mounds during play. Families deal with burning stings that sometimes trigger serious reactions. These insects cause billions of dollars in damage each year, and their range keeps expanding.

Many treatments rely on synthetic chemicals. Some work well, but people often hesitate to use them around food, pets or water. That hesitation leaves a gap. Researchers want gentle solutions that matter in the real world, not only in lab notes.

The strong scent of oregano oil

A team at the University of Mississippi decided to try something simple. They examined oregano, a common herb in many kitchens.

Oregano’s essential oil carries a strong scent, and the team wanted to know if ants react to it. They ran tests and watched imported fire ants avoid treated areas.

“Our study shows that a natural compound safe enough to flavor food can also manage one of the world’s most aggressive invasive species,” said Xing Cong Li, co-author of the research paper.

The group traced the effect to carvacrol, a sharp smelling compound inside oregano oil. The ants backed away from soil coated with the oil. They refused to dig or settle.

That reaction alone could help protect gardens, storage sheds and other sensitive areas. The tests have not included human skin, so people still need to handle the oil with care.

How oregano oil affects ants

The team wanted to understand why this reaction happened. They collected 21 compounds related to carvacrol. Each had a slightly different structure. Some barely bothered the ants. Others nearly matched carvacrol’s strength.

To dig deeper, the researchers built computer models. These models explored how each compound might interfere with pheromone signals.

Imported fire ants depend on these signals for nearly everything. If the signal breaks, the colony loses direction.

“Carvacrol and its analogs could serve as the basis for new, plant-derived repellents suitable for gardens, farms and even home use,” noted Li. The idea gives scientists room to shape new formulas with longer lasting effects.

Changing ant behavior with oregano

Imported fire ants threaten crops, equipment, pets and people. Their presence complicates daily life across huge regions.

Many households want methods that protect land without introducing harsh chemicals. Plant-based materials fit this need because soil microbes break them down faster.

Study co-author Abbas Ali explores natural compounds for pest control. He explained how this approach works. “The products we’re developing act as repellents – what we call digging suppressants in fire ants,” Ali said.

The suppressants block nest formation because the ants cannot dig through treated soil.

This strategy does not always kill insects. It changes behavior instead. Colonies leave the treated area and search for safer ground. People gain space without adding chemical pressure to the environment.

Challenges based on soil type

Soil type changes everything. Clay can hold scent for long periods, while sandy soil loses it quickly. Heat, moisture and wind shift results too.

Researchers test these variables one by one. They want treatments that behave reliably outside the lab.

Ali continues to examine seeds, leaves and plant resins. Some materials show soft but steady effects. Others offer stronger action that may help farms during stressful seasons. He also points out that placement matters.

A good product can fail if used in the wrong spot. Field crews now look at mound patterns, shade, soil texture, and time of year before applying treatments.

Future research directions

Future work may involve large outdoor tests in orchards, parks and neighborhoods. Teams may combine multiple plant compounds to build stronger protection.

The experts also want to understand how long each treatment lasts in heat, rain, or wind.

This research suggests something refreshing. Answers do not always require complex inventions. Sometimes a kitchen herb offers a path forward.

Oregano oil may give communities a cleaner way to push back against fire ants and protect land with less risk. The science continues, but the direction feels hopeful and grounded in everyday life.

The study is published in the journal Pest Management Science.

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