Children and staff at Mount Cotton State School, an elementary school near a rainforest in Queensland, Australia, have spotted wallabies, koalas and snakes over the years.

Recently, builders adding new classrooms to the school made a discovery that caught even the notoriously diverse fauna of Australia. The builders found a huge wooden moth that can have a wingspan of up to 9 inches.

The moth – fuzzy looking and mottled gray, with a passing resemblance to a popular stuffed animal – was found on the side of the new building.

“It was an amazing find,” said Meagan Steward, the school principal, in an interview with ABC Radio Brisbane that aired on Sunday. “That moth was something we hadn’t seen before.”

The children loved it, she said, and wrote fictional stories about the moth, including one about a giant insect that was eating one of the teachers.

The gray wood moth or Endoxyla cinereus is found in Australia and spends most of its life as a larva in eucalyptus trees that feed on the tissue. According to the Queensland Museum, they live as larvae for three years.

But as adults, they only live about a week – they die shortly after laying eggs and mating. They’re rarely seen, therefore, said Christine Lambkin, an entomology curator at the Queensland Museum who collected the moths as a child and estimated there could be about a dozen sightings of the moth in a year.

“I had to dissect and remove the contents of the abdomen, fill it with cotton and sew it up so I could add it to my collection and it wouldn’t rot,” she recalled. (Ms. Steward, the headmistress, said the moth found at the school had been returned to the forest.)

Adult moths do not eat. They have no functioning food organs and instead draw their energy from the fat reserves they accumulated in the larval stage, according to a museum data sheet on the moth.

They can sometimes be visible against street lights, according to the fact sheet: “Great excitement usually occurs when one of these massive creatures walks into house lights.”

They usually rest on the gray trunks of rubber trees, where they fold their narrow wings next to their bodies, camouflaging them from predators.

Women of the species are particularly tall – men are only half the size of women.

A female can weigh up to 30 grams, about an ounce, which is more than a few tiny mice or shrews, said Floyd W. Shockley, an entomologist at the National Museum of Natural History in Washington.

While the giant wooden moth has an impressive wingspan, it doesn’t have the widest, he said.

The white witch moth, which is found in Mexico and South America, has a wingspan of up to 30 cm.

The giant wooden moth’s large chest – about the width of a finger – makes it the heaviest moth, said Dr. Shockley. A female can carry up to 20,000 eggs in her belly.

Dr. Shockley said he was fascinated by the animal because, unlike humans and other animals, it spends much of its life as “immature” rather than as an adult. He said he was also impressed with the status of larval wood moths as a food source for some Indigenous Australians.

“You can eat them raw or you can cook them,” said Dr. Shockley. “Basically, the taste should be something like almonds.”

The school’s discovery of the moth could help entomologists gather more data on the distribution of the species, which remains a mystery, he said.

“I think any entomologist would be really excited to find these things,” said Dr. Shockley. “I’m a bug and that would still upset me.”