Asian Needle Ant: a New Allergy Threat in the U.S.

Photo: © Steven Wang all rights reserved

Invasive species are nothing new, but the recent spread of the Asian needle ant (Brachyponera chinensis) has captured the attention of entomologists, allergists, and public health officials alike.

Once confined to East Asia, this small, venomous ant has now been confirmed in at least 20 U.S. states.¹ With a sting capable of causing severe allergic reactions, including anaphylaxis, Asian needle ants may represent a new and growing threat to public health.

What Are Asian Needle Ants?

The Asian needle ant is a dark brown to black insect with reddish-brown legs and antennae, measuring about 0.2 inches in length. Native to China, Japan, and Korea, it was first reported in the U.S. in the early 1930’s. However, it wasn’t until the last two decades that populations began to surge and spread aggressively.^2,3

Unlike more familiar ant species that form visible trails, Asian needle ants forage alone and often nest in leaf litter, mulch, rotting logs, or even the soil near foundations, pools, and HVAC systems. The inconspicuous behavior makes early detection difficult, allowing them to establish colonies undetected until infestations become severe.⁴

A Sting that Pacts a Punch

Photo: © Steven Wang all rights reserved

What sets Asian needle ants apart isn’t just their stealth, but their sting. Though they are not naturally aggressive, they will sting when threatened, often if they become trapped in clothing or shoes. Victims describe the pain as sharp and lingering, sometimes more intense than that of a fire ant. While many insect stings result in minor localized symptoms, Asian needle ants have a more troubling reputation. Research has shown that about 2% of people stung by these ants can experience systemic allergic reactions.⁵ They are also more likely to cause an allergic reaction than a honey bee sting.⁶ In its native habitat, and increasingly in the U.S., there have been documented cases of anaphylaxis, a life-threatening allergic reaction marked by swelling of the throat, difficulty breathing, and loss of consciousness.⁷ This emerging allergenic threat is especially concerning for individuals already sensitive to insect venom, including those allergic to bees, wasps, or fire ants.

Spreading Across the U.S.

Initially established in the southeastern U.S., Asian needle ants have since been reported in Connecticut, New York, Pennsylvania, and as far west as Washington state.¹ Their ability to survive in cooler climates distinguishes them from fire ants, allowing them to invade new territories that were previously less susceptible to venomous ant species.

Their ecological impact is also significant. Asian needle ants compete directly with native ant species that play a role in native plant seed dispersal. This displacement can disrupt local ecosystems, particularly in forests and natural preserves.⁶

Identifying and Reporting Sightings

Because Asian needle ants do not form trails and nest discreetly, they can easily be confused with other ants. Look for small, dark ants with reddish legs and a shiny exterior. If you suspect their presence, take a clear photo and contact your local Cooperative Extension office or university of entomology department.

Several universities are collecting data on their spread, including the University of Georgia, Mississippi State University, and Virginia Tech. Submitting your findings helps researchers track infestations and develop mitigation strategies.

What to Do If You Are Stung

Stings often result in immediate pain, redness, and swelling. However, more severe symptoms may include hives, nausea, vomiting, dizziness, and difficulty breathing. If any systemic symptoms develop, seek emergency medical care immediately.

People with known insect venom allergies should carry an epinephrine auto-injector at all times, especially when spending time outdoors. Even if the device is used, it’s essential to seek emergency care afterward as symptoms can recur in a secondary reaction known as biphasic anaphylaxis.⁸

If you think that you or a loved one are allergic to any type of stinging insect, you can use our find a provider tool to locate an allergist near you to help with both testing and treatment.

Prevention and Control

Property owners can take several steps to reduce the risk of Asian needle ant infestations, including:

Removing potential nesting materials such as leaf litter, firewood, and rotting logs.
Sealing cracks in building foundations and around utility entry points.
Avoid stacking mulch or organic debris directly against your home.
Use caution when gardening or working in areas with soil and plant matter.

Professional pest management companies can use targeted baiting methods to reduce colonies. Unlike fire ants, Asian needle ants are less attracted to sweet baits and more responsive to protein-based baits.²

If you live in an area where Asian needle ants have been reported, stay vigilant. Learn to identify them, take precautions when working or playing outdoors, and talk to a provider if you suspect an insect venom allergy. For those already allergic to stinging insects, updating your emergency action plan could be lifesaving.

Article References

“Antmaps.org.” Antmaps.org, 2025, antmaps.org/?mode=species&species=Brachyponera.chinensis. Accessed 24 July 2025.
“Asian Needle Ant.” Entomology.ces.ncsu.edu, entomology.ces.ncsu.edu/asian-needle-ant/.
“Asian Needle Ant.” Purdue University – College of Agriculture, 2022, ag.purdue.edu/department/btny/ppdl/whats-hot/_docs/2022/asian-needle-ant.html. Accessed 24 July 2025.
Osborn, Tyler. “Residents Urged to Watch for Invasive Asian Needle Ants.” Ncsu.edu, 3 July 2025, clay.ces.ncsu.edu/2025/07/residents-urged-to-watch-for-invasive-asian-needle-ants/. Accessed 24 July 2025.
Pappas, Stephanie. “Invasive Asian Needle Ant’s Sting Is Painful, Can Cause Anaphylaxis.” Scientific American, 13 June 2025, www.scientificamerican.com/article/invasive-asian-needle-ants-sting-is-painful-can-cause-anaphylaxis/. Accessed 24 July 2025.
“Details.” Tsusinvasives.org, 2017, tsusinvasives.org/home/database/brachyoponera-chinensis. Accessed 24 July 2025.
Goodwin, Jenifer. “Ants with a Sting That Can Trigger Anaphylaxis Spread in U.S.” Allergic Living, 21 May 2025, www.allergicliving.com/2025/05/21/ants-with-a-sting-that-can-trigger-anaphylaxis-spread-in-u-s/. Accessed 24 July 2025.
Susan York Morris. “Everything You Should Know about Biphasic Anaphylaxis.” Healthline, Healthline Media, 22 Sept. 2015, www.healthline.com/health/allergies/biphasic-anaphylaxis.