Does Christchurch have a rat problem?

Reports of rats marauding the fringes of Christchurch's residential red zone and beyond have some residents crying plague.

But are rats in Christchurch really a symptom of the earthquake aftermath, or a normal wintertime occurrence?

Most of the residential red zone is vacant land. Most former residents have resettled and most houses have been demolished. The Canterbury Earthquake Recovery Authority (Cera) has bought the land.

A query on the TC3 Residents Facebook page yielded more than 20 reports of rat sightings from residents in blue/green zones.

New Brighton resident Bindi Donaldson wrote that rats were climbing the tree her deck was built around. "One was huge, thought at first it was a small cat", she commented.

Sarah Webb-Matenga, a Wainoni Rd resident, said she had lived in her house for 26 years and "had never seen a rat" - until they showed up at her house about three months ago.

She had seen them running across her grapevine and her son had heard them scratching in the ceiling of his sleep-out. Rats had also climbed the pipe beneath her bathroom sink.

Webb-Matenga believed her two-year-old dog, Eliza, who died suddenly on Sunday and had symptoms of bleeding, may have eaten a poisoned rat.

She had spent about $100 on rat poison in the past week, she said.

Webb-Matenga and others commenting on the TC3 Residents Facebook thread said they believed the rats were attracted to rubbish that had been dumped on abandoned properties.

Dawn Hendrikse, a service technician and business manager at Elite Pest Control, said rodents were attracted to places that were quiet and empty, with food and water sources.

However, demand for Elite's rodent control services had waned in the past 12 to 18 months.

"During the winter, it's really hard to gauge because there's always an increase," Hendrikse said, "but last summer, it had reduced quite dramatically.

"Certainly, people in properties on the cusp of red-zone areas tend to think that's where they're coming from, but I think it's normal activity for winter. During summertime, it will taper right off."

Cera said its call centre received, on average, one phone call or email a month relating to pest control.

Warwick Isaacs, Cera's deputy chief executive of implementation, said Cera was "not aware of a rodent problem".

It had received a few reports of rodents on Crown-owned land bordering green-zone properties, and had engaged pest-control services where necessary, he said.

"Property owners and occupiers are responsible for pest control on their own land," Isaacs said.

"This includes Cera, who is responsible for pest management on Crown-owned land in the residential red zone."

Cera encouraged people to report concerns of pests on Crown-owned land, Isaacs said.

The Press