WAILUA — An arborist has discovered some strange-looking ants on Kauai and though there’s some question about exactly what species they are, they’re most likely invasive.

In June, Eric Bowman, arborist and owner of Niu Mana Tree Care, was cutting coconut trees for a client on the east side when he ran across some ants he described as, “a cross between an ant, bee and spider.”

Bowman took to the internet, asking people on social media to identify the weird-looking ants and through some citizen research, pinpointed the species as yellow crazy ants.

Entomologists with the Hawaii Department of Agriculture analyzed a photo of the ants, and said they look more like carpenter ants.

Both species have been in the Hawaiian Islands, and on Kauai, for years, but they are invasive.

“They’ve been here for almost a century – at least – and are common on all the islands, including Kauai,” said HODA spokeswoman Janelle Saneishi. “Yellow Crazy Ant is also common in Hawaii and has been here for decades. It is very common on Kauai.”

She also said yellow crazy ants are very invasive and especially impact ground-nesting birds.

A month later, Bowman returned to the same property where he found the first cluster of ants — and the population has grown.

“I have a group of them in the back of my truck,” Bowman said on Monday, calling into the newspaper from the job site. “I’m watching them move. They have this erratic movement.”

He says he’s watching them spread throughout the coconut trees, colonizing each one.

“I came back this last week and found them in the neighboring lot,” Bowman said. “Now I have this old, wilted baby coconut in my truck bed and there’s 50 or 100 of them on there.”

Yellow crazy ants and carpenter ants look similar. They both have stripes on the thorax and have a yellowish cast to them. Extra long legs make them look almost spider-like and the thorax is bigger than the head by a long shot.

In fact, without an expert eye, it could be nearly impossible to tell the difference.

Carpenter ants usually nest in rotting wood or stumps that have been already eaten out by termites. Yellow crazy ants usually nest in coconut trees or in citrus, coffee and cinnamon trees.

According to researchers, yellow crazy ants are known for erratic movements when their nest is disturbed. They don’t bite, but instead spit acid to kill their prey. Carpenter ants are also known for spraying a toxic substance from their head, but the body explosion kills the carpenter ant.

Both are orange in color and somewhat translucent.

If you see what you think are invasive ants, or any other of the species on the Invasive Species List in Hawaii, there are a couple of ways to report the sighting.

First, freeze a specimen to send into the Department of Agriculture’s office on Oahu where entomologists can get a good look at the species.

While you’re freezing the specimen, call the statewide pest hotline, 643-PEST (643-7378) or go to 643pest.org. You can also call the Kauai Invasive Species Committee at 821-1490.

Contact the HDOA Plant Pest Control Branch on Kauai at 241-7138.

••• Jessica Else, environment reporter, can be reached at 245-0452 or at jelse@thegardenisland.com