The figure 4 trap has been used for hundreds of years and is one of the easiest traps to build and one of the easiest to remember how to build.
If you are ever stranded in the wilderness this is one trap that you do want to remember how to build. Other types of traps and snares may require a special material, such as string or wire, but the figure 4 trigger trap can be built using nothing more than a few sticks or twigs and a knife. This trap is taught in both civilian and military survival courses.
The figure four refers to the look of the trigger for the trap. It is made of three notched sticks that are configured to look like a number four. Anyone who has built one of these triggers should be able to easily remember how to build it again when the need arises. The trigger can be set to release with the slightest nibble or touch from rabbits, squirrels, birds or other small prey. The idea is to use the trigger to drop a heavy object on the prey, such as a large flat rock or a log, which kills the animal instantly.
The trigger consists three notched sticks: a vertical stick, a horizontal stick and an angled stick. The trigger can be built to any scale depending upon the size and weight of the object you are using as the trap. The vertical stick has a flat notch at the top that fits into a v-notch in the angled stick. The angled stick has a flat notch on the lower end that fits into a v-notch on the horizontal stick. The horizontal stick has a square notch cut into the back side that fits into a square notch on the front side of the vertical stick. One side of the heavy object used as a deadfall rests on top of the angled stick.
Although easy to configure, it does take a little practice to get the trigger set just right. The idea is to make it as sensitive as you can so that it is easily released when a critter nibbles on the bait.
It is important that the deadfall have some weight, but not be so heavy that you need to struggle to move it. A deadfall object should be easy to handle, but heavy enough to disable your intended small game prey. My preference has always been for using flat stones, such as slate or flagstone. Flat stones with a straight edge on the ground are more stable and do not tend to tip the trap to one side or another. You also want to be careful that you are not using a deadfall object that is so heavy that you might injure yourself while assembling the trap.
The notches should not lock the components together. The components should fit loosely and are held in place by the weight of the deadfall object distributing its weight through the components. The deadfall object rests on the top of the angled stick, which acts as a fulcrum and passes a small percentage of the weight to the sharpened end, which is held in place by the notch in the horizontal stick. This pulls the horizontal stick in that direction, but it is held in place by the square notches. When the intended prey nibbles at the bait, the sticks held by notches move and the trigger collapses.
You will also need some type of bait attached to the sharpened end of the horizontal stick. Study the game in the area and provide a type of bait that they may desire. If you have peanut butter or some type of fat, you will find that most small game and birds will go after that. Squirrels like nuts. Birds prefer seeds packed around fat or packed around something like chewing gum. A piece of bread is enticing for many small animals. Grubs or worms can make a tasty bait. If you have extra bait it can help if you spread a few pieces on the ground around the trap. That will help lure your prey into the trap after it consumes those.
Here is a true story about the versatility of the figure four trigger. About 25 years ago a friend who knew that I was a survival expert an outdoorsman called me because of a problem at her home. Her 19th century home was being renovated and some wide maple baseboards were removed, which exposed gaps in the floor and plaster lathe walls. Her brother’s pet hamster had somehow escaped his cage and crawled into a gap in the floor. This was on the second floor, so we had no access from below. I figured that the hamster was probably getting hungry, so I configured a figure 4 trigger out of pencils, used a cardboard box for the trap and peanut butter for the bait. We turned out the lights and within ten minutes the trap had been sprung and the hamster was safely back in his cage.