Scott Kemp first spotted glow-in-the-dark millipedes while bushwalking in the Illawarra 18 years ago.
He was completely unaware that the phenomenon had never been documented in Australia before.
"I was actually looking for biofluorescent scorpions, scratching around leaf litter trying to uncover them," Mr Kemp said.
He had ventured into suburban bushland after being tipped off about the glowing scorpions by a local tattoo artist.
"I had modified cars and liked neon lights, so I went out with a black light to look," he said.
"It was annoying that all these millipedes were glowing instead."
Millipedes in Australia are known to fluoresce under UV light, but bioluminescence — when organisms emit their own light naturally — has not been officially recorded in native millipedes before.
However, the millipedes Mr Kemp saw glowed on their own. Now, almost two decades later, his discovery has been flagged as a potentially undocumented, native species.
"When I first encountered them, I just assumed everything was known about everything to be known," Mr Kemp said.
"I didn't really think that I could discover anything new."
'Like something out of Avatar'
Amateur astronomer David Finlay has spent hours in the dark of night capturing glowing organisms with his camera.
His work is known to bioluminescence enthusiasts across Australia, which is how Mr Kemp recognised him while they were both chasing fireflies in Macquarie Pass National Park one night.
Mr Kemp asked Mr Finlay if he knew about the millipedes, and the next night they went out searching together.
Mr Finlay might now be the first person in Australia to photograph their bright blue glow.
"They flashed for one or two seconds when you disturbed them, and then curled into a ball like a defensive action," Mr Finlay said.
"There were so many of these millipedes that Scott's footprints were lighting up like a scene out of Avatar."
For now, the pair wants to keep the millipedes' exact location secret to protect the potentially native species.
New find likely native
La Trobe University entomologist, Dennis Black, is one of Australia's leading millipede experts and was part of the team that identified the leggiest species of millipede last year.
Despite only seeing Mr Finlay's photographs of the glowing millipedes, he was confident that this was an undocumented find.
"I'm not aware of anything that's been published on this," Dr Black said.
"But I would say there's very little chance they're an introduced species, but a native species."
Dr Black has seen the phenomenon once before, 25 years ago in wet forest near Eden in south-east New South Wales.
At that time, there were no records anywhere in the world of millipedes that could self-emit light. Dr Black put the glowing down to symbiotic bioluminescent bacteria either in or on the arthropods.
Since then, entomologists Paul Marek and Wendy Moore, from the University of Arizona and Virginia Tech respectively, have found millipedes of the genus Motyxia, native to California, are capable of bioluminescence.
"The chunky body in [Mr Finlay's] photos is very characteristic of Spirobolid millipedes, which are common east of the Great Dividing Range, but the Californian millipedes are in a different order," Dr Black said.
"I am convinced now that I was probably looking at the same beasts as Scott and David way back then."
Exact species may remain unidentified
While Dr Black hypothesised the millipede was of the order Spirobolida, it is unlikely to have a definite identification any time soon.
There are about 50 species of Spirobolida known from Australia, all named by overseas specialists.
"Unfortunately, there's no one in Australia who works on this order, so we may not even be able to do their taxonomy," he said.
"We've probably only described 20 per cent of the millipede species in Australia and given them actual scientific names".
For now, Mr Kemp has a few name ideas up his sleeve.
"I joked about it with my wife and kids, the only one that really sounds cool to me is the Scotty luminus," he said.
