Things that glow in the dark may usually be associated with Halloween, but now scientists are uncovering the chemical make-up of Australian mammal fur to work out what makes it light up under ultraviolet light.

While researchers have long-known that feathers, shells and even human hair are luminescent, the exact chemistry behind the glow was somewhat of a mystery.

Zoologists at James Cook University (JCU) used mass spectrometry to identify the compounds responsible for the photoluminescence, particularly the colour pink, in seven Australian mammals from far-north Queensland.

JCU zoologist Linda Reinhold said the team found the amino acid “tryptophan” found in bandicoots, quolls and possums was causing a bright pink glow.

“We wanted to find out whether the luminophores present in bandicoots might be common across multiple species,” Ms Reinhold said.

The study found both shared and unique luminophores and some yet to be identified. The team say in a paper published this week in the peer-reviewed journal PlosOne, that the glow of mammal fur may be far more chemically diverse than previously thought.

Rats, bandicoots, possums, bats, tree-kangaroos and many other creatures glow violet or blue under UV light, with Murdoch University’s iconic Quenda glowing a “bright pink” under UV light.

Ms Reinhold said porphyrins – one of the chemicals which causes fur to glow – is the precursor to hemoglobin or red blood cells.

Ms Reinhold said the tube-nosed fruit bat is probably the best candidate for future research.

A variety of species fluorescing under UV light.

In a previous study from 2023, Ms Reinhold tested if moonlight could set off the glowing fur and if different predators may use it as an advantage for catching prey.

Besides colour, she wanted to determine if nocturnal marsupials might use luminescence for communication or survival.

The study found that there is an evolutionary advantage to the trait for either communication or predation. It remains a “mystery”, Reinhold said.

According to the US National Center for Biotechnology Information, luminescence works by absorbing light and then releasing it again at a different wavelength.

Ms Reinhold described what her team observed in Australian mammals as being more akin to “phosphorescence”, which takes longer to release light.

This usually results in a dim light output, meaning if this phosphorescence were to have any effect, it would have to be during the day, when UV light is more present.