Thousands of toxic cane toads have been captured in Australia's northeast so they can be converted into fertiliser for farmers, an organiser of the second annual round-up said.

Toad Day Out's Lisa Ahrens said she was hopeful that 10,000 of the loathsome animals - the equivalent of one tonne of toads - had been captured and killed in the Queensland initiative.

"I'm hoping we did," she said from the northern city of Cairns.

The cane toad, which carries a poisonous sac of venom on the back of its head toxic enough to kill snakes and crocodiles, is regarded as a noxious pest in Australia because it wreaks havoc on the environment.

Ms Ahrens said Australians had little love for the warty amphibian which is known to kill domesticated pets and had no problems collecting the animals so they could be killed humanely.

"They just take over anything. They are quite industrious," she said of the toads. "They are an introduced species and they need to be out."

Residents were asked to collect the toads, which come out at night, on Saturday evening and then place them in plastic bags in their refrigerators. They were then, still alive, assessed as cane toads by organisers.

The toads were then killed humanely in freezers with their bodies to be used in the most part to create fertiliser for the cane farmers which have battled them for decades. Australia is beset by millions of cane toads after they were introduced to control scarab beetles in the 1930s.

Prolific maters, the toads eat anything and are incredibly tough, with all attempts to fight their spread - including driving cars over them and smashing them with cricket bats - having failed.

Ms Ahrens said the biggest toad hauled in to Cairns was a 18.4-centimetre-long monster which weighed close to half a kilo.

"It's as big as a kitten," she said, adding that the beast would be stuffed and used as a trophy in future Toad Day Out events.