WWF's Conservation Innovation Awards

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Ur-bins

Urban Rat compost Bins.

  • These are rotational compost bins that have a rat trap built into them. The rat finds its way into the compost bin, has a lovely feed and then when it wants to leave the way out is set with a standard pressure pad rat trap.  Here's a youtube clip all about it. https://youtu.be/DHYjBvDC-P4

Some of the best things about these units are: 

  • The user never has to touch the dead rat. This makes the trapping process more appealing to those of us who are a bit squeamish.
  • Because we visit the compost on a daily basis to throw out kitchen scraps the units get checked regularly and the trapping doesn't get forgotten about due to lack of kills (A common problem with community trapping)
  • The killed rats get disposed of in an easy and sanitary way (the compost becomes the bait and the rat becomes the compost)
  • Because we want to attract rats we can put things like cheese and meat scraps into the compost (things that people often keep out of their compost for fear of attracting rats☺)
  • These units are cheap and low tech to make so would be great projects for school children to make their own and in the process learn about the idea of Predator Free NZ. 

 

What conservation problem are you trying to solve?

The problems these units are designed to solve are urban rat populations (these have been shown to be controlled if communities become involved) and the amount of food waste that gets sent to the landfill unnecessarily (According to a 2009 study by the Ministry for the environment  200 kg a year per household )

 

How are you going to solve this conservation problem?

Through getting as many of these units as I can into urban households and getting young people enthused about predator control and composting food waste. A big part of making these units accessible is their low cost. By upcycling washing machine drums collected at metal recycling stations and combining them with CNC cut plywood and a bog standard pressure pad rat trap as well as scrap tires for the raised beds the whole system comes in at well under $100. Plus if I can source a wooden pressure pad rat trap there's not an ounce of plastic in the construction.

What makes your idea new and unique?

I have spent  many hours looking and haven't been able to find any examples of existing compost bin rat traps. 

Who will use your idea, and how will they benefit?

The main winners will obviously be the local bird populations but these units are great fun and urban households will benefit by having less rubbish to put out on the street each week, a decrease in rat populations nearby and a healthy vege garden. 

 

What tasks or activities do you need investment for? How would you spend a $25,000 grant?

The completion of 7 units for field trials and then rolling out an educational program offering workshops where kids can make and take home their own rat trap compost bins. This could be scaled up by working with metal recyclers around the country and establishing local coordinators to run the workshops. I would also like to create an open source tutorial on how to build a unit so that anyone wanting to make one has the information they need. This would include creating a CNC cutting file that could be used to create the kitset parts needed. 

Are you a New Zealand citizen or resident?

YES

I have read and agree to the Crowdicity Terms of Use, the Conservation Innovation Awards 2017 Supplemental Terms and Conditions, and the Crowdicity Privacy Policy

YES

List five other ideas posted in the challenge that excite you. Why?

The Urban Rat Project because it would work so well in conjunction with Ur-bins as well as being such a great coordination tool for community groups especially in terms of trapping pulses which I think will help to alleviate the trapping fatigue that occurs within community predator control projects.

Cacophony because as we move towards a predator free NZ food based baits will no longer be effective as the remaining predators will be spoilt for choice in terms of food but social lures will become increasingly irresistible as predator populations dwindle.

The one self-resetting trap that kills both Possums and rats because well Duh! ☺

Te Waananga Papa Taiao Paauaua because this kind of enterprise will help foster more conservation initiatives in the future and because young people need a sense of hope for and involvement in our environment.

Kiwi trail blazers because I would so love to have had this as a resource when my kids were young.

How could you improve your idea?

There have been some fantastic suggestions put forward for Ur-bins. Jenny asked if the heat from the compost would get rid of viruses carried by rats. I will get advice on how to test for this as part of the data we collect from the field trial.

Catherine wanted to know how long it takes for the rat bodies to break down. This can also become a focus of the field trials.

Jean-baptiste talked about making the Ur-bin a digital design so it could be CNC cut out of plywood and then James offered to help create a cutting file. Fantastic!

Michael from the Urban Rat Project has offered to add a reporting field for schools within his system so that school groups who build and take home their Ur-bins can compete and win prizes for their trapping successes. 

edited on Oct 11, 2017 by Hannah Smith

Leigh Nicholson Oct 3, 2017

Love the idea, not sure I want a dead rat in my compost

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Hannah Smith Oct 6, 2017

I LOVE having dead rats in my compost! I never see them and they grow great tomatoes! :)

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Leigh Nicholson Oct 7, 2017

I guess a dead rat is better than a live one!!!! Asnd if they grow great tomatoes - even better!!!! :)

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Hannah Smith Oct 7, 2017

Yes :)

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James Prier Oct 3, 2017

Like I said on my page it's great that there is more than one version of this, you definitely get my vote.

I've been working on composting ideas for a while now, more for inside the house that out but one of my favorite techniques is bokashi composting. You introduce an inoculated material into the food waste to breakdown the material much faster. The only thing other thing you need an anaerobic environment.

So maybe put an air tight lid on the lower bins you made and every time you dump from top to bottom you put the bokashi compound in. You'll break down those rats way faster.

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Hannah Smith Oct 3, 2017

That's a pretty cool idea. I'm trying to make this a no fuss system so will see how it goes on its own to start with.

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Hannah Smith Oct 3, 2017

wwfnewzealand and #ConservationInnovation

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James Wilson Oct 4, 2017

A bit of animal in any compost enhances the brew and very quickly breaks down into good soil. Love the idea. Picton Dawn Chorus want to become the first predator town in New Zealand and I can see this idea being widely adopted as we progress towards this goal.

The idea gets my vote.

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Hannah Smith Oct 6, 2017

Thanks James. I assume you mean predator free!!

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James Wilson Oct 7, 2017

Yes I did mean predator-free town. I hope we can trial one or two down here for you.

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Pavel Plotinnov Oct 4, 2017

Hi Hannah,
I really like your compost bin :)
At some stage we might be able to amalgamate our inventions :)
Going to vote for you!

Cheers,
Pavel

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Hannah Smith Oct 6, 2017

Thanks Pavel. I like your idea too. You must be pretty smart!

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Catherine McLennan Oct 4, 2017

You have my vote. I live on a suburban property so have avoided having a compost bin because of the risk of encouraging rats, much as I also don't like putting my food scraps into land fill. This would allow me to compost without that worry, and in fact I would be reducing any rat population in the area. Plus using a New Zealand designed and manufactured product is even better. Plus I like the fact that it's up on legs, so I could potentially move it if I needed to. And I love that you want to launch it through schools which is a great way to get buy in from the younger generation. I know my kids are much more environmentally aware than I ever was at their age, so this would be a terrific way to reward and encourage that and give them positive ownership of a conservation project. Well done Hannah.

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Hannah Smith Oct 6, 2017

Thank You Catherine for your comprehensive feedback! Maybe I could get you to trial one of the field units and give me your thoughts :)

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Tess Sheerin Oct 4, 2017

Great idea :)

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Lucy bowden Oct 5, 2017

Great idea! Got my vote.

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kim willis Oct 6, 2017

I live in the Waitakere Ranges and we have a large rat problem. To try and solve it my next door neighbour bought 2 Bengal cats. They may have controlled her rat problem but they are prolific hunters and I have now seen a decline in the native birds around my garden. This compost bin rat killer is the perfect answer. No poisons are needed and no introduction of cats which are indiscriminate killers of wildlife and pests. Thanks Hannah and good luck.

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Hannah Smith Oct 6, 2017

Thank you!! You sound like a prime candidate for one of my trial bins. If I get this off the ground I'll get in touch. I'm so sorry about your neighbors cats. That makes me so cross. We have lots of cats come into our property and I chase them off but I feel so helpless since its considered perfectly acceptable for them to roam freely killing as they go, just for fun half the time. :(

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Brent Beaven Oct 6, 2017

I am glad that people are looking at the issue of rats at compost bins as this will become an emerging issue as we start to build predator free urban communities. I am also very pleased to see that this WWF site has created some collaboration between your idea and James' compost bin killing machine.
My advice as we get one week out from crunch time.....either be specific about what differentiates your idea form James, or...consider the potential to join together with one application??
Brent

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Hannah Smith Oct 6, 2017

Thanks Brent. I've been working on this for some years now and have a working prototype whereas James just has a concept that he woumd like to develop. I'd be interested in seeing where he goes with it and would love to see another version developed but at this stage there's not much there that's of use to me. If I received the development funds most of the money would go towards getting these units into the community rather than developing a prototype which I've already done. Thanks again for your feedback H

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Brent Beaven Oct 12, 2017

Good luck Hannah. Good to see you get through all of the stages. Brent

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Hannah Smith Oct 12, 2017

Thanks Brent. Now's the hard part :)

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Jennifer Mcguire Oct 7, 2017

I love this idea. What better way to make a rich compost and cut down on pests at the same time. I would totally use it. I just wonder if the heat from the composting process would be high enough to kill the viruses carried by the rats? Will you be doing any research/testing on this in your pilot?

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Hannah Smith Oct 7, 2017

That is such an interesting point. Thank you so much. I will definitely make that part of the testing criteria. I will keep you posted and let you know when I start farming put the field trial units. H

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Jennifer Mcguire Oct 7, 2017

It might modify what the end use for the compost might be but never the less yours is a great idea which will totally work. Well done.

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Hannah Smith Oct 7, 2017

Thank you :) I've been a bit obsessed!

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Sophie preece Oct 7, 2017

Great idea! We have just moved to a small town section and I am wondering how to kick start the compost...this could be the perfect solution!

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Hannah Smith Oct 7, 2017

That's great Sophie. I will keep you posted and if you ever have a scrap washing machine to dispose of I'll send you the plans to make your own. :)

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Gerald Dickinson Oct 7, 2017

Hi Hannah,

Building a rat trap into compost heap is a great idea. I have this issue at home and need a better solution for it. I am not sure of trap design you are working on but one idea is to have vertical trap on side of compost (similar to down piping on house) This creates the only access route in and out of compost. Once rat frequents path then introduce trapping mechanism into top end of down pipe. Ideally a self resetting trap similar to good natures A24 using compressed air.Trap kills animal and drops to bottom of down pipe, disposal either by human or scavenged by cat.
Would this be a trapping unit that can be bought and added or would be a compost incorporated unit. Ideally a separate unit would be easier to maintain and move.

Beware having dead rats in compost heaps attracts flies especially during summer, if it is buried deep in the compost then it is not an issue.

Regards
Gerald

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Hannah Smith Oct 7, 2017

Hi Ged all good stuff. I love the good nature traps but want to keep the costs down and the pressure pad traps work well. Have you seen the YouTube clip? https://youtu.be/DHYjBvDC-P4 it shows how my units work. Thanks for your feed back x H

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Adriana Foreman Oct 8, 2017

great idea Hannah, and I like how you intend to propagate it through education and sharing

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Hannah Smith Oct 8, 2017

Thanks Adriana, yes I'm really excited about making these units super accessible. Plus I'm determined to make them entirely plastic free except for the actual rat trap. (Although maybe I should trial a wooden version?)

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Adriana Foreman Oct 8, 2017

yes! that's another good thing about your idea, hire you use recycled items. I'm not sure how easy it will be to procure a washing machine drum.... but the concept is commendable. maybe there are other options... I've seen braziers made out of gas drums... similar shape?

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Hannah Smith Oct 8, 2017

Good suggestion but washing machine drums are perfect because they are perforated which allows lots of air in but no flys and because they are designed to withstand water. They are much more lightweight than gas bottles and don't need to be cut. My local metal recycling depot gets about one scrap washing machine a day and let's me have them for $5 and takes back the rest of the machine once I remove the drum. I would like to offer metal recyclers all over the country a price per drum that would make it worth their while to remove the drums and make them available to c

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Hannah Smith Oct 8, 2017

Oops!!! Make them available to local colaboraters or schools to have Ur(bin making workshops. Thanks so much for your feedback ☺

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Catherine Taylor Oct 8, 2017

I am currently battling rats in my compost and love this idea. A natural solution on 2 levels! Well done. I would like to know how long it takes for the rat bodies to break down?

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Hannah Smith Oct 8, 2017

Hi Catherine. I'm not sure. I guess that would be part of the feild trial data. The good thing is once the rat is in your compost and tucked up in the raised beds it never gets seen again. I've talked to a

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Hannah Smith Oct 8, 2017

Oops! A local farmer and he used to throw whole sheep into his compost pile so a rat shouldn't be too much of a mission. In Canada they make compost piles on the sides of their highways to deal with roadkill moose and deer.

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Jean-Baptiste Natali Ginoux Oct 9, 2017

Low cost ideas makes this design more likely to be replicated! Talking about replication, would you consider turning them into a digital design so a large number of them can be easily cut by a CNC machine?

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Hannah Smith Oct 9, 2017

Yes that's exactly what I want to do. I need to find someone to help me with that. Is this something you are involved with?

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James Prier Oct 10, 2017

Hi Hannah

I really hope one of us gets the grant, it seems like such an obvious solution to use a compost bin to catch rats. And yes I think I may have gone down the same obsessive rabbit hole as you.

If you need help with CAD and CNC work I've got a ton of experience so could quickly turn your design into a set of files that could be router cut or similar production process.

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Hannah Smith Oct 10, 2017

That would be amazing! Plus I think we might have more luck getting past the originality milestone if we combine forces. I've written to Becky asking about this but havent heard back yet. What do you think?

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James Prier Oct 11, 2017

Hi Hannah

From other comments and further design I have narrowed my proposal down to a retro fitted lid for vertical compost bins. So not sure how well aligned the two products are now as a single proposal. We'll see what Becky says.

Either way I'd be happy to help you progress you design

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Hannah Smith Oct 11, 2017

That's great idea James. I look forward to seeing the final concept. Thanks so much for your offers of help.

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Becky Wilson Oct 11, 2017

The idea has been progressed to the next milestone

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raro Oct 12, 2017

Hi Hannah, generally it's considered necessary to have at least a cubic metre of materials in order to generate enough heat to make compost quickly. I'm pretty certain a washing machine drum will be of much less volume than that. I've some years experience making cold and hot composts and have no hesitation about adding small dead animals to a hot compost heap. They will break down within days when a pile is 60 or 70 degrees. It will be much slower and could be stinky and possible a health hazard at lower temperatures. Rats will quite happily live and nest in a warm/cool compost heap. You may find they don't try to leave for some time; consider how composters may feel about opening the barrel to find a live rat! Cheers and all the best with your trials.

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Hannah Smith Oct 12, 2017

Thanks for your feedback Raro. Yes the whole reason I got into composting was a sustained lecture by my brother over the course of a 5 hour car journey to Taupo. People do become obsessed by it. He lives in Australia and is a permaculture guru. He would build compost piles mostly out of carbon based materials 1 metre square. Then he would go and find some road kill and shove into the centre of the pile. He said as soon as he added the animal protein the pile would almost instantly become too hot to stick your hand into. My brews are much slower and colder but I've never had a rat "stay over" and there is no smell what so ever. It doesn't matter how long the rat takes to breakdown because it is buried in the garden bed and never gets seen again. I would love it if you were keen to trial one of the units. You could be my compost expert. If you follow me I'll keep you posted.

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Steven MacLeod Oct 13, 2017

Oh so brilliant

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Hannah Smith Oct 15, 2017

Thanks Steven. I'm having a great time developing these units :)

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BECS WILSON Oct 15, 2017

Such a great idea. Dead rats in compost so much better than live ones. : )

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Nigel Binks Oct 15, 2017

I like your idea. I was wondering whether you have investigated what the resulting soil is like with the incorporation of multiple rat bodies, or whether the smell of decaying rats dissuades other rats from entering the trap? Or what attractant might compliment this best?

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Hannah Smith Oct 15, 2017

Thanks for your thoughts. I guess it depends on how many bodies go into the compost. I would probably recommend that the trap only be reset once the current batch of compost has been emptied into the raised beds below. With our household this happens about once every 10 days. I wouldn't expect to have to use any attractant beyond the household scraps that go into the compost though I sometimes wish we weren"t vegetarian so I could put some enticing meat scraps in there. :)

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