An invasive ant species known as the Asian needle ant has expanded its range to at least 22 states across the United States, with recent confirmations in Louisiana and other areas. Entomologists reported the spread in early 2026, noting the ant's presence in the Southeast, Mid-Atlantic, and parts of the Midwest and West Coast.

Native to East Asia, including China, Japan, and Korea, the Asian needle ant, scientifically named Brachyponera chinensis, first appeared in the U.S. in 1932 in southeastern states. Over the decades, it has moved northward and westward, establishing populations in states such as Alabama, Arkansas, Connecticut, Florida, Georgia, Kentucky, Louisiana, Maryland, Massachusetts, Mississippi, Missouri, North Carolina, New York, Ohio, Pennsylvania, Rhode Island, South Carolina, Tennessee, Texas, Virginia, Washington, and Wisconsin. The ant thrives in moist, shaded environments like forest leaf litter, under logs, stones, mulch, and pavers near homes.

Workers measure 5 to 6.5 millimeters long, with slender dark brown to black bodies and lighter orange-ish legs and mandibles. Unlike fire ants, they forage individually without visible trails and prefer cooler, humid conditions, making them active even in shaded areas during summer. Colonies can span multiple nests and contain thousands of ants, preying on termites, other insects, and scavenging sugars or carrion.

The ant poses risks primarily through its sting, which delivers venom causing intense, sharp pain described as "liquid fire" that radiates and persists for hours. Reactions include swelling, hives, nausea, low blood pressure, and breathing difficulties. Studies show a higher likelihood of anaphylaxis compared to bee or fire ant stings, with 2.1% of stung individuals in Asia experiencing life-threatening symptoms like airway constriction, rapid pulse, dizziness, or fainting. Those allergic to other insect stings face an elevated risk. The ants sting defensively when nests or individuals are disturbed, often during gardening or moving debris, with peak activity in July and August.

Ecologically, the ant reduces native ant diversity and disrupts seed dispersal by preying on key forest species, potentially altering understory plant communities long-term. U.S. Forest Service entomologist James Vogt noted the species' ability to invade undisturbed forests.

Management focuses on avoidance and targeted control rather than eradication. Wear thick gloves when handling mulch or wood, and avoid nests in debris piles. Protein-based baits like Amdro fire ant bait or professional products such as Advion can be effective if applied precisely to foraging areas in spring. Experts urge reporting sightings to local extension services or apps like iNaturalist for monitoring. Those with sting allergies should carry epinephrine and seek immediate medical help for severe symptoms.