There are at least two major elements to any cage trap, one being function, of course, and the other, practicality.  Once the function is in place in a trap that catches well, the trap has to be user friendly, not too heavy, not too large, but as small and light as possible and still catch, hold and hold up.

Within the world of practical is stackable.  In order to be stackable there must be no external components, all parts must tuck neatly inside the wire box.  What this comes down to is engineering, problem solving.  As an inside out ADC operator, in the business for a couple of decades with small animals and a lot longer on beaver, I ran into the same obstacles, situations everyone else does.  Understanding the problems is step one, then figuring how to beat them comes next.  It was from my background with cage traps that making a stackable trap with internal components a must, nothing less, which is why everything we make has nothing protruding beyond the confines of the traps to catch on other traps in transit in the truck or on brush when the traps are deployed.  You can even pile them up when setting.
                                             

Above is a picture of a gray squirrel caught in a Comstock, double door, 4x5x24, push through, powered door, cage trap used with a Comstock nose cone to direct the squirrel into the trap.  Thanks for this picture taken by Tom in Iowa on his nuisance line.  These are called positive sets, used without bait or lure, that will catch an animal coming or going from a den.  Far superior to baiting, these sets rely only upon an animal moving from one location to another as this is his travel way covered by a "non directional" trap with two doors open to catch the squirrel either coming or going.  These traps are incredibly simple, inexpensive, yet the best trap available in a new double door trap, designed to work in any position.  They will take even small chipmunks and flying squirrel, rats and maybe even a large mouse.

This was squirrel number 5 taken from this setup.  Once the setup is made with the nose cone and trap support in place, traps can be removed and swapped out for a new trap quickly after a catch is made.  This supplants the need for separator tools and transfer boxes that have but one function, to hold an animal until release.  Furthermore, this removes the possibility of losing an animal during transfer, which can happen on occasion.

These traps are available now and will appear on the website soon.

Update on numbers, statistics for perspective

As of this week I have personally taken 268 beaver in the swim through 12x18x39 wire triggered, powered door cage traps in my own ADC business, which puts me squarely in second place.  A trapper in Massachusetts  has now taken over 600 beaver in two seasons, 400 and 200, along with more than 100 muskrats and plenty of otter.  I am still amazed that a trap this large with highly powered doors will also quite handily take small muskrats, even a couple of mink!  The Massachusetts trapper and one Washington State trapper each broke their old conibear records with Comstock Cages, which speaks volumes, showing the practical effectiveness of the device.

In my own business, though I am permitted to snare, use both conibears and foot holds, along with live traps like Bailey and Hancock, even shoot beaver under permit, the trap of choice remains our own cage traps because of the versatility.  They just plain work.  Typically I will load the truck with 6 or 8 cages only and head out on a complaint.  Setting from 2 to 4 is standard at a location.  Last year almost 90 percent of the 129 trapped beaver were caged in Comstock Cages, 116.  This year to date I have used the cages 100% of the time to take 23 beaver.

As with any device, at times there are "hang ups."  There is now one beaver that will require different equipment, which is always to be expected.  Like any visible device, as in square shy beaver with conibears, beaver will at times avoid a cage once they have seen others captured, even without springing a trap.  But, if the beaver is allowed to "calm down," by returning at a later date, weeks later, a formerly hesitant beaver may be trapped first night.

Species Specific Beaver Trap

As is, the 12x18x39 Comstock swim through beaver cage trap will take beavers, otters and muskrats.

Beavers may be taken alive when the Comstock beaver traps are set slightly out of water, an inch or two above the surface.  This, of course, means that all non-targeted species will also be alive and can be released.  I have released otter and muskrats.

When beaver trapping in a situation where taking live beaver is not required, where the traps are set fully submerged, it may be possible to take beaver only, while allowing non-targeted muskrats and otter to escape alive.

The cage wire is 1-1/2 inch mesh.  Having not tried this yet, the size of the opening or openings would have to be determined through trial and error, but I believe that a 3x6 opening would allow all muskrats and probably most or all otter to escape.  By cutting a hole or holes in the top of the cage when set upside down, small animals like otter and muskrats would go out through the mesh.  At the same time  even a 3x6 opening would be too small for beaver pass through.

If a flap was connected next to the opening, the traps would not have a single option, but the option to be used either way to take beaver only with the flap open and beaver, otter and muskrats with the flap closed.

The only negative to having this opening is that the traps will appear to be "sprung" from time to time when smaller muskrats and otter fire the trap and then escape.  Unless there is a trial cam at the site, there will be no way to tell what took place.  

Trigger Configuration for Catching Large and Small Animals

(Small Animals)    Our wire trigger traps can be made to work with both large and small animals.  When trapping a smaller animal, baby animals, chucks, rabbits etc., it's important to cover the entire opening with the trigger wires so that a small animal can not pass through the trap without hitting the trigger wires.  Wires should be placed close together, while extending across the entire cage opening.  If only small animals are targeted, longer wires that reach almost to the far edge of the trap can be substituted quickly.

A second way to force small animal into the wires is by simply narrowing the opening at the trigger with a vertical rod placed through the cage, top to bottom, just past the end of the trigger wires.  If the trap is set sideways with the trigger at the top, keep the trigger wires equidistant apart, less than 2 inches.

(Large Animals)     If large animals are targetted, raccoon, armadillo, woodchuck etc., the idea is the allow the animal to travel more deeply into the trap before it fires so that a catch is certain.  With the animal's body more centered in the catch box, success is likely, especially when using shorter 24 inch traps.  Rather than allow an animal to push on trigger wires with his nose at center and fire the trap quickly, it is best to bend the trigger wires back away from the side of the trap, while leaving a gap of perhaps three or four inches.  In this way the animal actually makes contact with the trigger wires with his shoulder, rather than with his nose or head.

If the trap is placed sideways, merely spread the wires away from center and leave a gap, again perhaps three or four inches.

Double Door Cage Traps / Positive Sets

The question:  Are animals hard to catch?  Answer, “Easy if you know how, impossible if you don’t.”  The best part of what I am about to relate, anyone can move from novice to expert in little more than the time it takes to set a trap.

As the self proclaimed “King” of double door cage traps, I have been an advocate of using equipment that exhibits the most versatility, multipurpose traps that can be used anywhere, in any manner, set the you choose to set them.  Some manufacturers make single door cage traps as their primary device, while double door traps appear as  more of a sideline trap.  All of our cage traps were first made to be double door traps and for good reason.  Double door traps have more uses, more options.  

Along with versatile/multi-functioning traps, I am a huge promoter of bait-less “positive” trapping of all kinds whenever possible, for a host of reasons.  Positive setting relates to den trapping, entry and exit holes where animals live, either free standing in the ground or in and under structures.  Cages with two doors may also be used along structure and for dig-outs under fences.  Double door traps used with positive sets without baits or lures is the most productive way to trap, sometimes taking animals in only minutes after traps are placed.  But, this does not prevent any trap from being set with bait if desired.  It just means that bait is most often not required for success, often better without it.  

Follow the reasoning.  Why would you set a trap in the open, with nothing on your side, to take a chance on an animal being interested in your bait or lure if there was a better location only inches away capable of catching the animal minus the element of chance?  Why would you try to make an animal come to you, replacing certainty with hope when you can often easily go to the animal with a double door trap in a positive set?  Answer, you wouldn’t.  It makes far more sense to use equipment and techniques that rely on no attractants, to take an animal that merely has to move, to catch him either coming or going where he lives.

Yes, there are situations that don’t readily allow for the use of double door traps or positive and trail sets, but not as many as you think once you begin to study and understand.  There are more opportunities than you realize, faster to set and will produce better.  All of these double door traps can of course be used with baits in either single or double door mode, all options open.  We do make single door traps.