100 ways to kill a rat

A part-time Department of Conservation job set three industrial design students on a path to save New Zealand’s native birds from predators.

A company set up by three industrial design students is revolutionising the way countries protect endangered native species from introduced pests.

Wellington-based Goodnature is leading the way in the development of smart traps that kill instantly and humanely, don’t require toxins and reset themselves.

Now celebrating its 10th anniversary, Goodnature has its roots in the part-time job co-founder Robbie van Dam took at the Department of Conservation (DOC) to help fund his studies at Victoria University.

Some of the existing pest traps were inhumane, labour intensive and had to be manually reset. There was clearly a need for something better. “So I sat down with my mate Craig and we worked out 100 ways to kill a rat,” says Robbie.

Robbie, Craig Bond and a third friend from university, Stu Barr, spent the next five years developing a reliable technology to kill pests.

“The challenge we set ourselves was overwhelming at first, and sometimes it still is. Product designers are never completely satisfied and that’s what keeps us innovating,” says Robbie.

Their eureka moment came when Craig used a gas canister to inflate a flat mountain bike tyre.

They incorporated the idea into their design, using a compressed carbon dioxide canister to power a polymer-reinforced piston that strikes the skull of the pest animal when triggered.

The animal is killed immediately and drops to the ground, where it is left to decompose or be scavenged. The piston returns into place automatically, ready for the next kill.

Controlling pests in New Zealand’s conservation estate, says Robbie, requires killing between five and 12 animals per hectare per year. Goodnature’s current models of trap kill twice that number before the canister has to be replaced.


Goodnature’s award-winning traps have wiped out rat populations in Native Island, off Stewart Island, and at Harts Hill, near Te Anau. They are used in New Zealand by DOC, local and regional councils, community groups and individuals. One-third of the traps are sent overseas for rats and mice and now to control species such as mongoose, mink and the grey squirrel.

Despite Goodnature’s success, Robbie and his colleagues still battle resistance to change.

“We’ve had technical challenges, but we’ve managed to resolve them remarkably well. The toughest thing of all has been getting people to change the way they do things, and to accept new innovations,” says Robbie.

Maintaining cashflow has also been a challenge. Robbie, Craig and Stu won a grant from DOC’s innovation fund in their second year of operation, and took on contract design work to keep the business afloat while they refined their product. Finding the right bank was an important step for the team. “We chose a bank that had a philosophy similar to our own and that supported New Zealand initiatives,” says Robbie.

While Goodnature started out as an exercise in problem-solving, Robbie says controlling pests to allow New Zealand’s native birds to flourish has become a lifelong passion for the team.

“We wrote business plans for the next one, five, 50 and 200 years. This is a challenge that is bigger than us; it’s bigger than any individual,” he says.


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