A formidable team of conservation dogs fondly known as the Rat Pack has spent four days scouring the seven islands of Ipipiri for rodents.
The dogs were working alongside Project Island Song in support of its mission to create an archipelago of pest-free island sanctuaries, project spokesman Richard Robbins said.
And to everyone's delight, except perhaps their's, they found not one single solitary intruder.
The four terrier-cross dogs had been trained to detect the scent of rodents, Mr Robbins said.
Others had been trained to detect the likes of stoats, "plague" skinks and Argentine ants.
"They are regularly employed to sniff out rats, stoats and other pests as part of their routine schedule to keep the islands pest free," Mr Robbins said.
"In the past year, three rat incursions have been detected on the islands, using an array of monitoring tools. If a pest has managed to swim or hitch a lift to the islands, the conservation dogs are called in to sniff out where the stowaway might be.
"Special permission is granted to let the team of dogs on to the islands.
"They are rigorously trained, and muzzled while working, to protect the precious native species present on these unique islands.
"Keeping the pests away is allowing Project Island Song to fulfil the aim of gradually reintroducing those species that would once have been found in abundance here.
"Tieke (saddleback), popokotea (whitehead) and toutouwai (North Island robin) are the first species to have been successfully relocated."
The Rat Pack was on call for use across the country, while Project Island Song was increasingly recognising the need for its own team of conservation dogs.