Koro rat trap?

[Cougartail]

Thanks for the clarification.

[BillyTraps]

Has anyone tried adding a second spring? if so, I would like to know the best way.

thanks

[huntingfool7]

I don't think there is room for an additional spring. 

It is a very strong, little rat trap.  Any critter that can fit inside the traps small frame will be dispatched without the need for additional strength.  The trap is meant to be placed in a box so the rodent has to enter from the front.  It is not meant to be a tunnel trap where the rodent runs through side to side.  Coming in from the front, the trap has passed foreign standards for humane dispatch.

If there is a weakness to this design it is in the trigger pan/dog.  It is not a very sensitive trap.  Often the target rodent will steal the bait off of several traps before tripping one.  I always gang set with two traps in a wire exclusion tunnel (one trap facing each direction).  I pulled one job yesterday.  2 of 4 traps had the bait stolen.  The 3rd trap had the culprit.

Picture came from a foreign site and depicts the use of the larger koro trap.  It's interesting that they use the larger trap in this box and then restrict the entrances down to a size that would be covered by the smaller trap. My exclusion boxes are made of wire but they are set up similar to this. 

[Humptulips]

Has anyone tried adding a second spring? if so, I would like to know the best way.

thanks

I would caution anyone against doing anything more than minor modification. The law that encompasses these traps references "common rat and mouse traps". If we go modifying the traps they will no longer meet the definition of "common". IMO adding an additional spring will invalidate their categorization as a common rat trap.
I do believe the trigger needs to have something done with it in order to use it on animals like mink, marten, civit and muskrat. I have used them with the pan unmodified and they spring too early. The animal needs to get farther into the trap before they trigger or the jaw will hit them in the face and push them out of the trap.
If you cut about 1/2 the pan off they will get far enough into the trap to get a neck catch at least with civits. I have not used them on other animals and it will take some experimentation to see what works best.
As said above they need to be used in a box and oriented so the animal enters from the front. I do not think they need a second spring as they are very strong.

Next year the Department has registered their intent to make a rule defining "common rat and mouse trap". Please do not screw this up for us by trying to make this into a trap it is not. Very minor modification is as far as we dare go.

[flyfishWA]

So, I have a koro set next to a little pond. there is swamp grass along the top of the pond where I have my trap set. the pond has crawdads and salamanders in it. their is a small rocky creek that basically drys up in the summer that goes out of the pond. today when I checked my koro, the box was pulled about 4 feet closer to the pond. the area around the box from where it had been to where it was when I got there was all tore up and the chain wrapped up in the grass. the chain is attached to the box. the trap was inside of a little tunnel through the grass which was about 5 inches wide by 5 inches tall. nothing was in the trap but it was snapped off and the beaver leg I had for bait was also in the tunnel. a couple feet farther down the tunnel it goes into the water. I can't figure out what it could be, any ideas?

[JakeLand]

I’m guessing your trap was set close to the front opening of the box? Could be a cat or a coon reaching in

[Humptulips]

Sounds like a good place for a mink. Let's assume a mink was in it. Two things could have happened. It didn't get caught but pulled the bait out, bait got caught and it ended up pulling bait out of the trap.
Other option, trapped mink and it wasn't in the trap far enough, maybe hit its nose or head  and it pulled out.
If the trap was out of the box possibly the animal had a hold of the bait, trap whack the animal and animal pulled trap and bait out and eventually  pulled out of trap.
Head scratcher! Never had anyone catch a mink in one yet so it is still an experiment.
Any chance you could show us a picture of the scene.

[UrbanTrapper]

I had a similar experience in a Marten area. Next time I set one I'm goint to put a trail camera on it in video mode.

[flyfishWA]

I think now that it might have been a coon.

[ibuyre]

I am almost positive I had one set off like this by a coon.... It hit his paw and he just pulled his paw right out, just like if he was hit with a victor rat trap. I had it set by the water in a big ball of roots (and it was in a homemade box), hoping to get a mink or weasel. But instead I had a sprung trap, and racoon tracks everywhere.

[Trapper John]

Well if you want to make money trapping moles it works on them
JC   

[JakeLand]

Alls I can say is cut the cable off and throw it away and hook up a small chain or nail the trap to the box !! I lost a trap and a marten tonight and then t snowed 2+ feet since it was caught. The cable pulled through the ferrel ( crappy design) I’ll be taking all of them off and replacing with small chain
Going back up tomorrow with the dog to dig and search. Anyone got a metal detector?

[Trapper John]

Alls I can say is cut the cable off and throw it away and hook up a small chain or nail the trap to the box !! I lost a trap and a marten tonight and then t snowed 2+ feet since it was caught. The cable pulled through the ferrel ( crappy design) I’ll be taking all of them off and replacing with small chain
Going back up tomorrow with the dog to dig and search. Anyone got a metal detector?

I had a cable break away just pulling up a mole trap out of a hole with dirt on it. 
I took everyone I have and hammered the ferrules shut.  That solved the cable problem.
I would recommend to everyone that has or have purchased a Koro Traps to do the same thing before putting them out.
Like Jake said, crappy design and I say bad inspection on Koro part.
JC   

[JakeLand]

I did double crimp them at home and it looks like really cheap cable cause there is strands still in the ferrel

[Humptulips]

Every time I have talked about them I have said to cut the cable off and toss it. No need for it anyway.
I drilled a hole on the bottom front of my boxes and wire them to the box and leave a tail to attach to a tree or bush.