Iíve always had an interest in primitive hunting and trapping as its one of the earliest examples of mechanical engineering e.g. windlasses, springs, pulleys and levers. The selection of materials with the correct properties to meet requirements e.g. wood, bone or stone. This interest is purely theoretical as I have never used these techniques in the wild. I would also add that in normal situations you should NOT use these techniques in the UK as some are illegal and others require the correct permits, licenses or the land owners permissions.Back to Index
Figure 9.3.0: Box trap
1. Image : reference Ė Camp Life in the Woods and the Tricks of Trapping and Trap Making by W.H. Gibson
"There is probably no more familiar example of the trap kind than that of the common wooden box-trap, better known, perhaps, by our country boys as the Rabbit trap. A glance at our illustration will readily bring it to mind, and easily explain its working to those not particularly acquainted with it. These traps may be made of any size, but, being usually employed in catching rabbits, require to be made quite large. They should be made of hard seasoned wood Oak or Chestnut is the best and of slabs about an inch in thickness. The pieces may be of the following dimensions: let the bottom board be 20+7 in.; side board, 20+9 in.; lid board 19+7 in., and the end piece of lid 7 in. square. The tall end piece should be about 16 inches high by 7 broad." W.H. Gibson
Box traps vary from the upturned box propped open with a stick tied to a long piece of string we all tried as children to the professional live capture traps used in "pest" control and scientific studies. Note, snaring is probably the simplest and the most efficient method of hunting, however, as an amateur Iím not always happy to use them. The main reason is the risk of capturing none target species e.g. cat, badger, fox etc. I know that if you set a snare on a suitable run, if its correctly sized i.e. not too big and if its at the correct height with a stop / breakaway to prevent capturing a leg of larger creatures then the odds of getting a non target species are very small. The problem is there are a lot of 'ifs' in that statement, Iím not a professional and things can and do go wrong at times. Therefore, one possible alternative to snaring is the box trap. The obvious disadvantage of these traps is their size and complexity when compared to the simplicity of a snare. However, they do offer a guaranteed non-lethal method of trapping different species. Reading around the subject of box traps two important considerations are the size of the trap and the trigger mechanism. The size of the trap is important for three reasons. Firstly to exclude non-target species i.e. it should be large enough to allow the target species to enter, but small enough to block undesirable / non-target species. The second is that the entrance must be large enough as to not deter the animal from entering i.e. even if the entrance is physically large enough for the desired species to enter some creatures do not like confined / enclosed spaces and will not enter, somewhat conflicting with the first requirement. The final requirement is that the trap must be long enough to allow the animal to fully enter before triggering the door mechanism, if not the animalís body may prevent the door from closing correctly e.g. jamming on the back of the animal allowing it to escape. Doing a little research on the web recommended trap sizes for Rabbits, Squirrels and Rodents are given in figure 9.3.1.
|Target Species||Length (Inches)||Width (Inches)||Height (Inches)||Distance from door to trigger (Inches)|
Figure 9.3.1: Box trap sizes
Figure 220.127.116.11: Ground Squirrel Box trap
1. Image : reference - Trapping the California Ground Squirrel by Everett E.H. and Henry S.
Figure 18.104.22.168: Ground Squirrel Box trap plans
1. Image : reference - Trapping, Handling, and Marking Fox Squirrels by L.Baumgartner
Typically commercial box traps are made out of wire mesh, with either a metal or wooden internal frame. An example is shown in figure 22.214.171.124 which is designed for capturing ground squirrels. Alternatively, DIY box traps are normally constructed from thick wooden planks e.g. 0.5" - 1" thick. An example is shown in figure 126.96.36.199 which is designed for capturing fox squirrels. The first box trap I made is based on a mixture of features from the previous designs, as shown in figure 9.3.2. This trap was intended for Squirrels using a pressure plate trigger mechanism and an externally opening front door. The theory being that an externally opening door would allow me to make the box a little shorter. The box is made from Pine planks 15" x 5.75" x 0.75", secured together using six 45mm wood screws top and bottom. Note, six clearance holes are drilled and counter sunk in the top and bottom planks i.e. front, middle and back on both side edges, screws pass through these holes and are screwed into the middle of the side planks. The end plate is made from the same wood 4" x 5.75" x 0.75", whilst the front door is made from slightly thinner wood 3.75" x 5.5" x 0.625", secured to the box with a standard door hinge (perhaps a little on the large size). Tip, I needed to remove some of the wood behind the hinge where it attached to the door to allow it swing freely. Note, the materials used in the making of this trap were greatly determined by what I could find at the back of the shed, would of made the trap a little bigger if given the choice. When the planks were screwed together the inside of the box was quite dark, therefore, decided to drill two 0.75" holes on each side and one in the back plate, this allowed light in and the scent of the bait out, also serves as ventilation holes for the captured animal. The door is held open via a cord with one end looped around a metal pin which projects out of the top of the box, the other attached to a 'U' nail hammered into the bottom middle of the door. The metal pin is attached to the pressure plate such that when the animal climbs on it the pin is pulled down releasing the cord allowing the door to fall. The pressure plate is made from a piece of wood 3.75" x 2" x 0.625". Its bottom hinge is made from a 5" nail. Using a hacksaw the head of the nail is cut off, the remaining rod is cut in half. A hole of the same diameter (slightly smaller) is drilled into each side of the pressure plate at its base. Into these are hammered the sections of nail such that a 1" length of rod comes out of each side. These then pass through holes drilled into the side of the box allowing the pressure plate to rotate 180 degrees about this axis. You can see the pressure plate in position in the second image, in the second row of figure 9.3.2. Note, found it was best not to drill out the holes in the side planks based solely on measurements from the end of the plank as when screwed together the sides can be slightly misaligned, best to screw the side planks into position, drill one hole, place the pressure plate in position marking where the second hole needs to be drilled on the opposite side plank i.e. such that the pressure plate is square and level. Note, drill a good sized clearance hole to allow the nail to rotate freely. A 'U' shaped nail is then hammered into the top edge of the pressure plate onto which a loop bent in the end of the metal trigger pin is hooked i.e. pressed closed with pliers so that it can not come off. Note, when attached to the pressure plate the trigger pin is long enough such that it will not fall out of the top plate even when the pressure plate is flat, this makes setting the trap easier as you cant see inside it when built. The disadvantage of this is that the pin projects a long way out of the top plank when set. To increase the triggers sensitivity a small block of wood is screwed on above the hole, reducing the pins effective length. To prevent the door opening when closed a thin metal plate is screwed onto the base of the box. This catch is made from the lid of a tin can. The sides are trimmed off to form a rough rectangle, along each edge a 5mm section is folded over, hammered flat and soldered in place to form a 1" x 2" rectangle. Note, the folded section removes the sharp edge and adds strength. The front 0.5" is bent over forming the catch. When the door is released the door compresses the catch which springs back as it passes over it, catching the bottom of the door preventing it from opening. Note, to ease the compression of the catch I round off the bottom inside edge of the door helps, outside edge must be square to ensure that the door canít be pushed open. I also found pulling the door back further (higher) so that it had more time to build up speed as it closes helped prevent it jamming on the catch. Note, in some examples Iíve seen elastic bands are hooked onto the base of the door and the side of the box, this extra helps the door close quickly.
Figure 9.3.2: Box trap version 1
After building the first box trap I can see why the planks need to be 0.5" Ė 1" thick, in order to prevent splitting as you screw on the top and bottom planks. However, they are a little on the thick side, making the trap very heavy. Another consideration is that the planks need to be thick enough to prevent the animal chewing its way to freedom. Kept rabbits as a child, so I know if they put their mind to it they can chew through a piece of wood, even so 0.5" is a bit on the thick side. As an alternative to the plank method I made box traps 2 and 3 out of split Bamboo, as shown in figures 9.3.3 Ė 188.8.131.52. This is a lot lighter, however, its also a lot thinner increasing the risk that the animal can chew a hole large enough to escape. Are they too thin, only time will tell? The trap in figure 9.3.3 and 184.108.40.206 was designed to capture Rabbits, 28" x 7.5" x 7.5" with an internally opening door and rear trigger pin. Split Bamboo has a '(' cross section, to prevent slipping when bound together the internal flat edges face each other. Lashed together these edges dig into each other locking them into position. The lashings are tied such that the cord wrapped around the cross members is square '||', and crosses 'X' over the side bars. This is repeated three times, instead of tying each lashing off individually the cord is wrapped around cross bar until the next side bar lashing position. This is repeats for all side bars. Finally a single clove hitch and over hand knot are used to secure the binding, a coating of varnish locks it all together. The front door hinge is constructed from a Pine branch approximately thumb thick. A recess is carved into each end, into which a cord is looped to secure the door in position. To hold the door open a Bamboo bar is tied to the back cross member, this then passes through the box hooking under the door, holding it up onto the top of the box. The other end of the bar is hooked under the trigger pin, onto which the selected bait can be attached, as shown in the top left frame of figure 220.127.116.11. The trigger pin has a top and bottom notch such that if it is pushed or pulled the Bamboo bar is released allowing the front door to fall. Note, to prevent the securing and trigger bars being lost they are tied to the cage, the string securing the trigger pin must be long enough to allow sufficient movement to allow the trap to be trigger. To stop the door opening itís longer than the height of the box such that it bottoms out on the base of the box. When closed it hangs at a 30 Ė 45 degrees.
Figure 9.3.3: Box trap version 2 components
Figure 18.104.22.168: Box trap version 2 setup
Figure 22.214.171.124: Box trap version 3 setup
Another classic box trap design is shown in figure 126.96.36.199. This style of trap uses a seesaw trigger mechanism allowing the door to fall vertically. To increase door weight the top and bottom bars are made from Pine. The advantage of this style of trigger is that overall trap length can be reduced as you no longer need to allow room for the internal door to swing down as in figure 188.8.131.52. This box trap is 16.5" x 5.5" x 5.5". Below are some useful documents on tracking ive found on the web (due to possible copyright conflicts these are only accessible from the local machine) :
Figure 9.3.4: Trapping environment
Deadfall traps kill by crushing, which results in a set of conflicting requirements for the trap. To crush the target animal you need a large weight, however, this places a significant load on the trigger mechanism, making it less sensitive. Hair triggers can be made or set, however, again this makes the trap less stable and more susceptible to false triggering due to slipping in the trigger mechanism or movement due to the wind. Therefore, there is more of an art in making these traps then first impressions may suggest. Its not just a matter of finding a large weight, there is an optimal balance in selecting just enough weight to kill the target animal, therefore maximizing the sensitivity of the trigger, especially important for the smaller mammals e.g. rabbits etc. In the past avoided deadfall traps as they are illegal in Britain and require a significant amount of material. The main item being the weight. This is typically made from a large rock, or log, both of which can be difficult to find. However, came across an area that had been clear felled with a lot of rabbit sign, as shown in figure 9.3.4. This had the advantage that there was a lot of cut wood lying around of the required sizes i.e. both for the weight and the trigger mechanism. Also lots of well used rabbit trails leading from the surrounding woodland into the new grass areas.
Figure 184.108.40.206: Deadfall trap - version 1
When Iíve been shown how to make these traps before one thing that is sometimes not shown in the books is the anvil i.e. the bottom log. This is shown in the middle of the top frame of figure 220.127.116.11. This ensures that when the main weight falls the animal is trapped between two hard surfaces i.e. the weight doesnít just push the animal into a patch of soft grass. To hold the anvil in position I used four wooden pegs hammered into the ground each side of the log top and bottom. The trigger mechanism is a standard design shown previously in the cage trap section. To ensure that the trigger mechanism didnít just spin round when the trigger bar is pushed from the side I hammered the main upright into one end of the anvil. Note, this was quite easy to do as one the end of the anvil was a little bit rotten. Alternatively it could be hammered into the ground, the main uprightís length adjusted accordingly. When set I found that the wind or any small movement caused by slippage of the main weight would falsely trigger the trap. To prevent this I added two upright stakes either side of the weight, stopping any sideways movements. The trap now worked ok, however, it raised an interesting point. Securing the main upright into the anvil (or the ground) to prevent rotation and adding the two side uprights slowed down the speed that the weight fell. This was due to the weight rubbed against the side uprights as it fell. It also had to push against trigger mechanism slightly, all of which slowed its decent. The weight still fell quickly, however, from observing how fast rabbits can move when required, Iím not convinced its fast enough. The original intent had been to place the trap across an existing rabbits trail, such that when the rabbit tried to jump over the anvil it would push against the trigger bar, springing the trap. However, I also found that you required quite a significant force to trigger the trap, combined with the falling speed problem, again not sure it would work as intended. Going back to my original sources on deadfall traps one thing that is common is that the trigger bar is baited. This would make a lot of sense to me after these tests. Having a baited bar means your not relying on the animal brushing past to trigger the trap, rather the animal will be actively pulling at the bar, providing the required force to trigger the trap.
Figure 9.3.5: Fenn trap
Came across a series of these traps during a walk across White Moor and Black Moor Rig. As this is a shooting Moor Iím guessing looking at the size of the entrance these are for rats.Back to Index