Special fences built around dams in arid parts of Australia could help eradicate the menace of cane toads, according to new research.

The toads, regarded as poisonous pests, are drawn to the dams by the need for water and die in large numbers if fences hold them back, scientists said.

The animals were brought to Australia in the 1930s to get rid of beetles.

They have since spread from Queensland into the Northern Territories, New South Wales and Western Australia.

Their numbers have grown because they have almost no natural predators and their toxins kill native animals that normally feed on frogs.