Experiences with AT220

With regard to experimenting with additional / replacement lures in AT220s …
Here’a comment from one of our trappers back in 2021 when the AT220s were in their infancy!

I recently cable-tied raspberry-flavoured cereal bait blocks on top of the mesh directly above the bait tray in all of my ATs, so that when the liquid bait ran out there would still be something there to attract possums. It does seem to have worked, but there is a big flaw in the plan. The AT220 takes quite a long moment to fire after the beam is broken because the wheel has to turn that last little bit before the tang lets go of the striker plate. When there is a dribbled trail of liquid bait for a possum to lick up to and including the bait tray its attention stays on the bait which keeps it in place long enough for the trap to wake up, the wheel to turn and the striker to fall. But I have just watched a video of one of my traps which had no liquid left, only the cereal bait block. A possum hopped up on the ramp and sniffed at the bait block but it did so tentatively, bobbing its head up into the cage repeatedly as it tried to find its way to the food. The trap fired in between bobs, when the possum’s head was not in the cage, and the trap went off right over its head. I don’t think I’ll be seeing that one again.

I am pretty sure that there was an increase in catches when I put the bait blocks into traps that also had liquid bait in them. But I don’t advise using bait blocks without at least some liquid bait in the bait tray.

Cheers, Tony

Thanks Tony, interesting observation. I didn’t know the trigger delay was that long. Useful to know.

Hi Dan, that would have been quite a while ago, like May 2021. I have just become aware of a blockage with my trap, which is an upgraded version from last August when NZAT updated the trap and software for me. They are always working on improving, and very good at responding and helping. Quote from my latest correspondence today:
"I will attach instructions on how to reverse the pump so it will blow back any blocks in the line. We have recently put a larger elbow onto the bottom of the bottle (where 90% of all blockages occur). If you like, I can send you a new elbow ( and the tubing needed) to replace the one on there so the block should not occur again. ( if this is ok, how many do you need )

Also, we have just changed our bait system on our new traps to a pouch system, if you are interested in converting to that, we have retro-fit packs available for $35 and they come with a Tray, Pump, fully loaded pouch and the required screws, zip ties, instructions, etc. You will also get a new lid without the bottle hole."

First try swapping the pump wires and running the pump in reverse. (Only works on the newer model Sorry)

Swap wires.
Plug battery back in.
Push button 3 times to get amber light.
Press and hold to run the pump.
Look down into the bottle till you see it bubble.
Replace wires, it should now run normally.

How do you make your Nutella mix? Ratios and ingredients?

Definately agree with making it easier for the rat to access.

Hi Dan, I’d tried a homemade nutella recipe too., but it failed. I strained the peanut chucks out, mixed with peanut oil, but it separated. Keen to know how you did it!


As requested Liquid nutella lure.


I’ve had an AT220 for 2 months now (Haruru, Far North). I got it to try and kill some rats living in our roof, and it worked within a couple of nights! I then moved it outside our chicken coop to kill possums I could see on camera raiding the feeder. For some reason its only killed one possum, but several more rats, and a few mice too. Another possum may have been wounded by the trap, as fur all over the place - but no dead possum nearby, or blood for that matter. I’m a little surprised/disappointed it hasn’t got more possums yet - may try dusting some cinnamon around.

The AT220 is killing around 4x as many pests as my A24 (19:5), with the AT220 getting possum/s and mice too, as well as more rats.

Yes, most rats get stuck in it unfortunately, and I think the possum I got too. It could be nice if the curved-bar at the bottom was more of an angled ‘slide’ made of plastic or metal wires. I’ve also had mice get ‘mashed’ into the corner by the sensor and in the spring too. Poking them out with a stick usually works, and rain seems to clean things up mostly.



Thanks Alex, great hearing your experiences and insights. On possums, I attach a metalized reflective bag nearby, to attract the possums. I know it works (trail cam) but I can’t say it necessarily encourages the possums to put their heads in the trap. Cinnamon is always worth a go, although you might put off rats - not sure how strong the evidence is for this one way or another.

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Hi Alex, just out of interest do you still have the trailcam on your AT220? How often do you inspect the trap? Do you get pigs in your area, which can be very partial to dead possum?!! Lots of fur can often be as a result of one possum getting caught and then another one attacking it while its hanging there … just a thought … cheers, Tony Oh, and do you know what version of the trap you have? The most recent upgrade was meant to help stop smaller pests from getting stuck in the mechanism.

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Hi Tony, I didn’t have the camera there recently due to weather and battery charging etc. I may put one back again. I check the trap every day as its on a small lifestyle block, near an area where a few people live. There are pigs in the forest and sometimes farms nearby, but they never come into this ‘residential’ area. I only bought the trap a couple of months ago, so presume its the most recent type. Last night I had a mouse wedged above the bait bath, so poked out with a stick. Cheers, Alex

Thanks Alex. If you bought it from NZAT then I expect it’s the latest version. Any doubts, send them an email, they are very good at responding and commenting if you are concerned about small pests getting stuck. Cheers, Tony

More comment on AT220 here In an ideal world - #19 by david.swann.new.zeal


Thanks so much for your insights and for the liquid nutella lure recipe. When you get some experience with your apple-cinnamon lure, please share that as well. I’m curious to see how it goes.

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We’ve got a fleet of 150 AT220 traps that are proving really effective - and that was just based on carcass counts. I’ve been doing some analysis to compare carcass counts with AT220 computer counts with Celium Node counts… and found that we’re undercounting kills. For small predators, we’re only identifying 20% of kills; for large predators, around 60%. That’s significant for two reasons - the first being to monitor progress on our journey to a predator-free Motupohue, the second being that we’re not doing justice to the amazing kill rates of the AT220. I’ve produced a report on this. Let me know if you’d like a copy.

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Yes please! tonygchad@gmail.com thanks

Yes please to the report. maungatapu3@gmail.com
I have found that the AT220 often records a definite possum kill as a rat kill, so undercounting possum kills for sure. No way of checking rat counts though.
These traps are awesome though.

Yes Please , can you send to macblack@xtra.co.nz , much appreciated, Neil

David, it’s very generous of you to share your findings. Is there any way you could post a PDF copy on this site. I ask because it would be of interest to a great many people, some of whom will be reluctant to post their email addresses. Quite understand if this is not possible :slightly_smiling_face:

Thanks Dan. How do I post a PDF onto the site?

Good point, I am asking TrapNZ.