(NEXSTAR) – Just when you almost forgot about them, the so-called “murder hornets” are back.

The hornets, officially known as Asian giant hornets or Vespa mandarinia, were first found in North America in 2019, on Vancouver Island in British Columbia, according to the U.S. Department of Agriculture. More confirmed sightings followed in 2019 and 2020, in both Washington state and British Columbia.

In 2021, the first dead Asian giant hornet was found in the U.S. in June, though experts believed it was likely an old hornet from a previous season, the Associated Press reported. But on Wednesday, a resident of Whatcom County, Washington, spotted what was confirmed by officials as the year’s first live sighting of an Asian giant hornet, in the town of Blaine.

A resident of Whatcom County, Washington, sighted the first live “murder hornet” of 2021. Officials say it was attaching a paper wasp nest — a common behavior. (WSDA)

“This hornet is exhibiting the same behavior we saw last year — attacking paper wasp nests,” said Sven Spichiger, the managing entomologist with the Washington State Department of Agriculture (WSDA), in a press release. “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.”

The venom from a murder hornet, as its name indicates, can be fatal to humans in extreme cases and mass attacks, the WSDA explains. As the largest hornet species on earth, the Asian giant hornet’s stinger can also penetrate a traditional beekeeper’s uniform and deliver more toxins — and substantially more pain.

The species, native to East Asia and Japan, kills an estimated 30 to 50 people per year in Japan alone, with most deaths resulting from anaphylaxis, sudden cardiac arrest or organ failure, per a report published in Clinical Toxicology in 2009. It’s unclear how the Asian giant hornet migrated to the Pacific Northwest, but experts believe the hornets may have found their way to the U.S. on cargo shipments.

Both the USDA and the WSDA, however, say murder hornets are not usually aggressive toward humans but will sting if provoked, threatened or handled. To that end, the WSDA encourages people to refrain from approaching or swatting at Asian giant hornets, which can be identified by their length (between 1.5 and 2 inches), their orange heads with prominent eyes, and their black-and-yellow- or orange-and-yellow-striped abdomens.

Samples of dead Asian giant hornets are laid out by researchers on May 7, 2020, in Blaine, Washington. (Elaine Thompson/Pool/AFP via Getty Images)

People are also encouraged to leave any area where they are observed.

“If you encounter several hornets, run to get away from them or dive into dense brush to make it harder for them to get to you. If a hornet flies inside your vehicle, stop the car slowly, and open all the windows,” the WSDA writes.

In the case of a sting, or multiple stings, victims are instructed to wash the site of the sting(s), apply ice, and call 911 if severe symptoms (including swelling of the face or mouth, tightness of the throat, or trouble breathing, among others) develop.

Those who experience an anaphylactic reaction are urged to call 911 and immediately inject an EpiPen.

To curtail hornet activity, residents of Washington state are also being told to make their environments less attractive to the species by covering food or drinks while eating outdoors, using wasp guards on bird feeders and properly disposing of garbage, food scraps or pet droppings. The WSDA further warns against using especially “fragrant” hair products, cosmetics or perfumes.

The Washington State Department of Agriculture says Asian giant hornets are usually between 1.5 and 2 inches in length, and have large orange heads with prominent eyes. They also have orange-and-black or yellow-and-black striping on their abdomens. In the photo seen above, WSDA entomologist Chris Looney displays a dead Asian giant hornet next to a smaller, native bald-faced hornet in 2020. (Elaine Thompson/Pool/AFP via Getty Images)

The WSDA has set up an online portal for residents to report possible hornet activity at agr.wa.gov/hornets, which will be used to help officials track and set traps in affected areas. Reports of sightings can also be emailed to hornets@agr.wa.gov or phoned in at 1-800-443-6684  

One other thing to note: As dangerous as the hornets are to humans, they’re much more of a threat to honeybees. Just a small group of the hornets can destroy a honeybee colony in hours by literally decapitating the bees with their mandibles, National Geographic reports. This phase, appropriately, is called their “slaughter phase.”