Residents in Katherine have been warned to stay away from a colony of fruit bats that arrived in the town late last month, as they could carry the Australian Bat Lyssavirus, a disease that can be transmitted to people if they are bitten or scratched.
Habitat destruction or changing climatic conditions could have driven the bats into the area, John Burke, a senior wildlife ranger, told the BBC.
They also may have been attracted to the area about 180 miles south of Darwin by native flora, he said.
"Obviously in the town area there's a lot of exotic plant species that are fruiting and flowering throughout the year," he said. "So it's more like a drive-through [for bats], I suppose, a drive-through take-away."
The lyssavirus is carried in bat saliva, health officials said.
Northern Territory Center for Disease Control Director Vicki Krause said if people are bitten they should wash the wound thoroughly and seek medical attention as soon as possible.
A vaccine is available and is effective if given immediately, she said.