What Are 'Murder Hornets'? Size, Sightings and What They Look Like

The first sighting of so-called "murder hornets" this year has been reported in Washington state.

Also known as Asian giant hornets, the report was made by a Whatcom County resident on August 11.

After entomologists from Washington State Department of Agriculture (WSDA) reviewed the photograph of a hornet attacking a paper wasp nest, it was confirmed to be an Asian giant hornet on August 12.

The WSDA will set traps to try to catch it and track it back to its nest.

Traps have already been set throughout the state and there had not been any detections so far this year.

What Are "Murder Hornets" And What Do They Look Like?

Asian giant hornets make a nest
Asian giant hornets (also known as 'murder hornets') make a nest in a tree trunk Getty Images

Asian giant hornets are not native to the U.S. and are an invasive species.

They are more commonly found in areas of Asia, from India to Japan, and have even been spotted in parts of Russia.

It is not clear how they first arrived in North America, though one theory is that they may have been accidentally transported in shipping containers.

They are among the largest species of wasp in the world. They typically have an orange head and a dark thorax with yellow, black and brown bands across their abdomens.

How Big Are Murder Hornets?

Queens of an Asian giant hornet colony are larger than the rest in the nest, growing up to two inches long.

The workers are slightly smaller, usually measuring about an inch and a half.

Asian giant hornet size
A person holds an Asian giant hornet (also known as 'murder hornets') to show its size Getty Images

Are Murder Hornets Dangerous to Humans?

A social species, they live in colonies and usually build their nests underground and fiercely defend them.

Unlike other species, they attack in groups making them far more dangerous. Their stingers are long and capable of puncturing thick protective clothing like those often worn by beekeepers.

The amount of venom a colony can inject through sustained stinging makes them a danger to young children and people with underlying health conditions, though hornets do not often seek out humans and pose a much larger threat to honeybees.

When hunting bees they enter a "slaughter phase" and a small group of Asian giant hornets can kill an entire hive of honeybees in a matter of hours.

Japanese honeybees co-evolved alongside the hornets and have developed a defense mechanism, by collectively surrounding the hornet and vibrating, suffocating it.

Much of the world's commercial honey production is dependent on European honeybees, however, which have no means of fighting off these violent attacks.

Where in the U.S. Have Murder Hornets Been Spotted?

This sighting in Washington is the first of 2021 and was found approximately two miles from the site WSDA eradicated the first Asian giant hornet nest in the United States in October 2020.

As the site is also about half a mile from the Canadian border, the British Columbia government will be setting traps to catch any hornets that are found there.

So far, there have been no confirmed reports of Asian giant hornets in British Columbia.

What Should I Do If I See a Murder Hornet?

Both the confirmed sightings of Asian giant hornets in the last year came from reports from members of the public.

First spotted in 2020 attacking a paper wasps nest, WSDA managing entomologist Sven Spichiger said Washington residents who have these types of nest on their property should be extra cautious.

A paper wasps nest hangs from tree
A paper wasps nest hands from a tree branch Getty Images

"If you have paper wasp nests on your property and live in the area, keep an eye on them and report any Asian giant hornets you see. Note the direction they fly off to as well," he said in a press release.

If you see a murder hornet, you should report the sighting to your state's Department of Agriculture.

It is best to move away slowly and calmly as swatting at them may make them more likely to attack.

What Should I Do If I'm Stung?

The sting of an Asian giant hornet can deliver a lot more venom than other wasps and even damage tissue.

They are able to sting several times and it may hurt more than other types of wasp sting.

If you do get stung, wash the sting site with soap and water, and ice the area to slow the venom's spread.

You may want to consider taking an antihistamine if you are experiencing itching or swelling, and should consult a doctor quickly if you have multiple stings or an allergic reaction.

If you experience lightheadedness or dizziness, impaired breathing or shortness of breath, difficulty swallowing or a tight throat, facial or mouth swelling, or blue skin, call 911.