As winter weather creeps in, rats are creeping out people in the capital.
Wellington backyard trappers are posting pictures of their catches and some of the rats they have caught measure up to 50 centimetres long.
One rat trapped in Aro Valley was described as being "the size of a small possum," in a post to a community Facebook page.
- Hordes of rats the size of cats infest Auckland suburb of Titirangi
- Rat infestation not confined to Titirangi as populations double across New Zealand
Predator Free Wellington's director James Willcocks says the rats are sizeable.
"There are certainly a lot of big specimens around," he told Newshub on Tuesday.
He says there are two types of rats in New Zealand - ship rats and Norway rats. Norway rats are the chunkier of the two.
"[Norway rats] can get up to half a kilogram," said Willcocks.
Willcocks says the increased presence of rodents is due to the mega mast - a phenomenon where trees and plants produce an excess of seeds which means more food for rats.
"More food on the ground means more breeding," James Willcocks told Newshub on Tuesday.
Although the mega mast is a contributing factor, it's not the only reason rats are on the rise.
"We see spikes around this time of year as [rats] look for more food and they start coming inside to look for warmth."
Predator Free Wellington provides free rat traps to people throughout the city - all it asks for in return is data on what you catch.
It has distributed 8000 traps around 44 suburbs in the capital.
With 6,500 of those reporting their catches via social media Willcocks says it's hard to tell if the rats are bigger and more common than usual or if there's just more people sharing their data.
"We do see a correlation around people with more involvement, so it's hard to say which suburb has the most rats," Willcocks told Newshub.
He says in July Predator Free Wellington will launch a full-scale operation to make Wellington the world's first predator-free capital city.
Estimates are it will take ten years.
The operation will begin in Miramar and use bait stations and trapping.
2000 traps are already in place in Miramar and in July bait stations will be laid on a 50 metre by 50-metre grid across the entire peninsula.
Traps will be laid of a similar grid of 100 metres by 100 metres.
"We're about getting to zero and preventing reinvasion," Willcocks said.
Newshub.
