Ants are a threat to cane toads.
The cane toad's invasion of Western Australia may one day be halted by a carnivorous native ant, ecologists have found.
University of Sydney scientists have discovered that cane toads are far more susceptible than native frogs to being killed and eaten by the Australian meat ant.
The ecologists' research - just published in the British Ecological Society's journal Functional Ecology - reveals a chink in the cane toad's armour that could help control the spread of the alien invasive species across northern WA.
Professor Rick Shine and his colleagues compared habitat use and activity patterns in meat ants, juvenile cane toads and seven native Australian frog species.
The research team found found that, unlike the native frogs, cane toads were poorly equipped to escape the tenacious meat ants.
"The spread of cane toads through tropical Australia has created major ecological problems," Professor Shine said.
"The ideal way to control toad numbers would be to find a predator that kills and eats toads but leaves native frogs alone.
"However, bringing in a predator from overseas might have catastrophic consequences, like those that occurred when cane toads themselves were brought in.
"So we've explored an alternative approach - to see if we could use a native predator."
Meat ants are abundant around tropical water bodies, and the tiny native predator has been seen eating small toads.
The scientists found that found cane toads opted to live in open areas and were active during the day, patterns that matched meat ant activity.
By contrast, native frogs are nocturnal and are safely ensconced in vegetation or other shelters during the day, when meat ants are on the hunt.
Professor Shine said that cane toads were also less equipped to escape attacking meat ants.
Using a specially-built runway, the team tested the frogs' and toads' sprint speed and endurance.
They found that compared with the quick and nimble native frogs, cane toads' hops were shorter and slower because they had shorter shin bones.
The results are interesting because they reveal the cane toad's Achilles' heel - a weakness that could be exploited to help control the spread of the toxic pest.