Pest control products are flying off the shelves in hardware stores as an influx of critters coincides with a 'mega mast' in our forests to fuel an infestation.

Department of Conservation principal science advisor Dr Graeme Elliott said households were typically plagued with more rats and mice around this time of year, as temperatures started to drop.

"There's a thing that happens with rats and mice every autumn - they make a bit of a bolt for the houses no matter where you are."

This year, Elliott said, this occurrence coincided with a 'mega-mast' in our forests. A mast is when trees like the beech tree seed, a mega-mast is when this seeding is heavy and widespread across the country.


Rats and mice would come out in force in spots close to forest areas, to feed on an abundance of seed lying on the ground.

"For residential people it's not going to have much impact at all, unless you're someone who lives actually in the forest," Elliott said.

This occurrence would, however, likely impact people living in rural areas.

Elliot said heaviness of a mast was largely dictated by climate.

Hardware store Mitre 10 was experiencing a seasonal rise in sales of pest control products, as New Zealanders worked to keep their homes free of mice and rats.

Chris Fisher, group merchandising manager, expected the double-whammy of factors attracting these critters, to drive this seasonal rise up even further.

"In an unprecedented situation like this, there is a two-fold need for Kiwis to take action and get their pest control sorted around their home," Fisher said.

"Nobody likes to see rats and mice around, so it will be about protecting the home from pests, but also about supporting the wider nationwide effort to keep rodent numbers in check."


When it came to pest control products, Fisher said things had advanced from the traditional "bait and trap" options.

"There are now very sophisticated systems that are safe for the whole family (pets included), non-toxic, low maintenance and, where the Goodnature traps are concerned, humane."

Fisher suggested traps by Kiwi brand Goodnature as a humane alternative to traditional mouse and rat traps.

Goodnature co-founder Robbie van Dam said their A24 rat and stoat contraptions were initially created to help DoC control stoats and wild rats during mast season.

"It kills them instantly," he said.

"Then they fall out and the striker, the thing that hits them, moves back and it's ready to go again."

Van Dam said these were popular with both households or rural property, as they were effective killing both rats and mice.