Asian needle ant with potentially life-threatening sting spreading across Pacific Northwest

Gardeners, hikers, agricultural growers, and more – a heads up! There is a new bug in town – the Asian needle ant.

The ongoing warming of the planet is helping this invasive ant to spread into more places, including Washington and the Pacific Northwest. This past winter was the third warmest on record. The U.S. Department of Agriculture (USDA) reported this aggressive ant has made its way and is emerging across the Pacific Northwest.

What is the Asian needle ant?

The Asian needle ant is native to China, Japan, and the Koreas, according to the USDA. It was first discovered in the U.S. in 1932 and has become more prevalent in a number of southeastern U.S. states. Now it is here.

This ant is about 0.2 inches in length, is shiny, either dark brown or black in color, and has lighter orange-brown legs. It likes to nest in undisturbed forest areas, particularly under or within logs, stones, or leaf litter.

In more urban areas, it likes to nest around homes and businesses under mulch, pavers, landscape timbers, and more.

Impacts

The Asian needle ant is another stinging ant. For humans, its sting can result in a life-threatening allergic reaction.

Native ants help disperse seeds through forests, gardens, agricultural fields, and more. The Asian needle ant dominates and pushes out other ant species, and as a result, reduces this critical seed distribution.

In forests, this impact can have long-term negative effects on forest undergrowth at a time when the threat of wildfires continues to grow, thanks to our warming planet.

What to do

For humans, simply avoid these ants. For those vulnerable to allergic reactions if stung, carry epinephrine and use it to avoid anaphylaxis.

The allergic reaction called anaphylaxis has a number of symptoms, such as:

• Skin reactions, including hives, itching, and flushed or pale skin.
• Low blood pressure (hypotension).
• Wheezing, difficulty breathing.
• Swollen tongue or throat.
• Nausea or vomiting.
• Dizziness or fainting.
• Weak or rapid pulse.
• Symptoms such as a feeling of impending doom.

If suspecting a reaction to an Asian needle ant sting, seek immediate medical attention since the reaction could be life-threatening.

The Asian needle ant is one more hazardous critter to be aware of when around your home or business, taking a walk or hike in the woods, in agricultural fields, and more.

The USDA reported researchers continue to assess the impacts of the invasive ant on people and the environment, as well as exploring ways to control the ant in areas where people are most likely to encounter it.

Sadly, as with many invasive species, it appears the Asian needle ant is here to stay and is another nasty critter to monitor when outdoors.

Ted Buehner is the KIRO Newsradio meteorologist. Follow him on X and Bluesky. Read more of his stories here.