About podiTRAP

The podiTRAP came about from…


For Reference = The inventor, Pouri, is pronounced ‘po-dee’ hence the product name.

Inventing a new kind of trap can be a slow kind of process. Sometimes you don’t even know you’re on that journey until you’re well on your way. Take the podiTRAP for example. 
“I never expected it to be where it is now,” says its inventor, Pouri Rakete-Stones. “It’s evolved into this big monster project!”

Pouri is an engineer by trade. He spent 10 years as a fitter/welder, doing research and development work on machinery, before getting involved with Hawkes Bay kiwi conservation and outdoor education organisation ECOED in 2010.

Not only did engineering and conservation come together at that point, but that was when Pouri and his wife Wendy first worked with then-General Manager Al Bramley. Al is currently CEO of ZIP (Zero Invasive Predators). Pouri, Wendy and Al also worked together during the early development stage of the Poutiri Ao ō Tāne project, a sister project to Hawkes Bay’s Cape to City. It was on this project that they started talking about what sort of trap they wanted to use for their 8000 hectares predator control programme.
“We had the idea of using a run through tunnel trap,” Pouri explains, “So I started working in my garage to see what I came up with. We came up with some ideas of what we wanted. It had to have good usability. It needed to be easy for farmers, landowners or even volunteers to service and the trap needed to be DOC 250 size because we wanted to include ferrets in the target species. So I developed a flip open lid for the tunnel so that the whole thing folds open.”

Pouri Rakete-Stones notes trapping results from a prototype podiTRAP.

PodiTRAP version 1 – proving the tunnel concept, but before the handle

podiTRAP version 3 - with a handle

PodiTRAP version 3 with the introduced handle

 Kiwi were also a factor in the tunnel design.   “We had to consider the length of the tunnel and the size of the entrance hole so that kiwi couldn’t reach the trap inside,” says Pouri.

The team then tested the tunnels, with DOC 250 traps inside, against the standard DOC 250 setup, with 50% of each trap type in their predator control network.

“The data collected over the trial showed that tunnels were the way to go,” says Pouri. “The tunnels were catching more ferrets and 2 times as many rats. The number of stoats caught in each was about the same.”

When the Cape to City project started in 2015, there were aspects of the prototype traps that the project team wanted to keep – the run through tunnel and the easy, flip-open lid – but other factors that still needed to be improved.

“The traps needed to be easy to set,” says Pouri. “The DOC 250 traps need a tool to set. They can be dangerous and hard for volunteers to set.”

Pouri’s solution was to change the design, introducing a handle.

“The handle on top of the tunnel was attached to the DOC 250 trap inside so that the trap could be set from outside,” he explains. “The handle on the outside also works as a ‘flag’. When the trap is set, the handle is up, so when you’re servicing the network you don’t need to stop at all the tunnels. It makes in quicker and more efficient to service the trapping network.”

The new handle feature worked so well that even Pouri’s 12-year-old daughter could safely set the traps.  “It’s also locking,” says Pouri. “When the handle is up and the trap is set, you can’t flip open the lid.

“I hadn’t been thinking in terms of product manufacture,” Pouri says. “Metalform helped develop a new shape and box size so that it was robust and stronger – but still keeping the key design features.”

While Metalform has manufactured other products for the conservation sector, the podiTRAP is the first kill trap they’ve worked on.

“Years ago the firm used to make something called a ‘jam-gun’ for pest control,” says Campbell, “And nowadays we build componentry for pest-proof fencing, fence capping for the fence at the Cape Kidnappers sanctuary.”

With Metalform on board, the next design step was getting the podiTRAP NAWAC (National Animal Welfare Advisory Committee) tested as a humane trap for killing ferrets – one of the target species in the Cape to City predator control project. 


“In 2016 we took the trap to Lincoln and put it through its paces,” says Pouri, “And it failed three times. It was a good process,” he says. “It tested the boundaries and we took it away and sent it back to Metalform and they were really good and made changes in a couple of days. Then it failed again, so we had more ideas on how to change it, like increasing the spring strength.”

As the spring size increased, the trap then needed to be re-engineered for the increased spring tension. By the time the podiTRAP passed the NAWAC test as a ferret trap on its 4th test cycle the springs were 4 x stronger than a standard DOC 250 trap. The standard ferret test weight for the NAWAC test has recently risen from 0.900kg to 1.800kg, this makes the new NAWAC test standard much more difficult to pass.

“It was a 3 month process,” says Pouri, “And the 4th time it was tested it passed with flying colours. It’s now got very big, strong springs and the podiTRAP, along with the DOC 250 which was NAWAC-tested about 10 years ago, are the only traps which have passed the NAWAC test for ferrets.”

Other modifications to the trap included a redesigned shape for the handle so it was easy to reset. Once the design had got its NAWAC ‘tick’, 1000 traps were made up by Metalform and are currently being field-tested in the Cape to City project.

“In the final product Metalform came up with a design that was plastic-injected, not made of plywood, so it lasts longer,” Pouri adds. “And that allows the traps to stack on top of each other for transport on a quad-bike okay” he explains.  “With the ply traps you could carry 3 or 4 at a time but with the new, modualised plastic they’re light and you can  carry at least 20 at a time.”



A line up of the traps that have been built thru many years of R&D and testing.

podiTRAP is a result of good ol’ kiwi ingenuity

supporting the Predator Free 2050 initiative