Northern Territory researchers are importing 250 quolls from Queensland to understand whether they learn to avoid eating cane toads or are just born that way.

For reasons unknown, Queensland quolls have adapted to living with cane toads, while NT quolls continue to eat the poisonous invasive species.

Quoll numbers in the NT have been devastated by the arrival of the cane toad, which was introduced to Australia in 1935 in northern Queensland and have now spread across the NT to Western Australia's Kimberley region.

Since 2007 researchers at the University of Technology Sydney and the Territory Wildlife Park and have been putting a select band of Northern Territory quolls through a training program to make them "toad averse".

Queensland quolls, however, seem to be naturally more prudent, and researchers are trying to understand whether that is due to a genetic adaptation.

"Everywhere else where there are cane toads particularly here in the Top End they're basically decimated northern quoll population," Territory Wildlife Park ranger Damien Stanioch said.

"For some particular reason quolls in northern Queensland have adapted to living with cane toads.

"Whether that's because of a genetic adaptation or a behavioural adaptation we don't know.

"Once they're bred here at the park we will be crossing Queensland northern quolls with Territory northern quolls."

If there is a gene for being toad averse, it should pass to the cross-bred quolls.

"Toads have a number of pressures on them not only cane toads, but if we can at least eliminate one they stand a really good chance of coming back," Mr Stanioch said.

Trained quolls avoid cane toads in the wild

The training program for making Northern Territory quolls "toad averse" involves gradually introducing the animals to cane toad bait laced with a chemical to make quolls feel sick.

The introduced cane toad is poisonous and has been held responsible for native animal population declines. ( ABC News: James Purtill )

"We give them a small piece of toad that is laced with a tasteless odourless chemical," Mr Stanioch said.

"It eats the toad portion and returns to its den box and sleeps it off.

"The next morning it feels a little bit unwell.

"A few days later we repeat that program.

"When the quoll eats it the second time it has another adverse and negative response.

"Usually after the third time it has eaten cane toad and gotten sick the quoll learns to avoid toad," Mr Stanioch said.

The park has released a "couple hundred" trained quolls into the wild in the past few years.

"Studies have shown the second and third generation released into Kakadu have been surviving and living alongside cane toads," Mr Stanioch said.