The discovery of potential rat poo on an previously predator-free island has prompted conservationists to head out in force to rule out any rodent infestation.
A researcher found the droppings on Sealers Bay beach on Codfish Island/Whenua Hou, off Stewart Island, this week.
It has prompted a "full-scale incursion response" from the Department of Conservation.
Whenua Hou is 3km from Stewart Island and has been predator-free since 1998.
![Whenua Hou is 3km from Stewart Island and has been predator-free since 1998.](https://www.nzherald.co.nz/resizer/v2/U4WZ2V2U5EYVBWNR4SWOF6IZUI.png?auth=4b32028cadd17377dc9e2823a008880f511ef4094fb41aec116764059dc2c51b&width=16&height=11&quality=70&smart=true)