Summarize this article in one sentence.
This is the wire that will capture and kill the rabbit in your snare, so it needs to be strong enough to hold the animal. While you can use any long and bendable wire, a thin metal wire works best. While easier to work with, rabbits can chew threw many thin ropes and cords, making metal the best option. Bend one end of the wire back on itself to create a simple loop, no bigger than an inch. You can wrap the wire around your finger to get the shape and size right. There should be roughly 2–3 inches (5–8 cm) of extra wire at the bottom of the loop. This is your slip-knot loop. Wrap the excess wire from the loop around the wire at least 5-6 times to snugly secure them together. This is the most important part of the trap, and the loop needs to be strongly attached. When done, it will resemble a balloon on a string.  The best way to test the strength of your loop is to put a pencil into the loop and then pull it apart. If the loop comes undone then you should retwist the wire to create a stronger loop. Use pliers to clamp the wires together for added stability if you need it. Feed the opposite end of your wire into the small loop you just made. Your whole wire will now resemble a large circle. Pull the end of the wire through the loop, shrinking your circle until it is the size of your fist, roughly 6–7 inches (15–18 cm) across. Your wire will look like a yo-yo on the end of a string. It should be elevated roughly a foot off the dirt and placed in a narrow corridor, such as a small footpath or a trampled trail in the forest. Your snare will hang from this to trap the rabbit.  Felled trees, low hanging branches, or iron bars will all work. Make sure your bar is secured or heavy enough that a small rabbit couldn’t pull it away. The loop should be hanging from the trap so that it is 7–8 inches (17.8–20.3 cm) off of the ground. Your trap will resemble a noose hanging from a rafter or bar. As the rabbit jumps through the loop its weight will pull the loop tightly shut and kill the animal. Using large branches, block off the space underneath and to the sides of your snare, forcing them to jump through your loop. You want to block off all the space except the one in your snare.
Cut a 2.5ft  piece of wire, rope, or cord. Create a small loop at the end of the wire. Twist the end of the wire at the bottom of the loop to hold it in place. Take the opposite end of the wire and push it through your slip-knot loop. Keep pulling the end through your slip-knot loop to make a noose. Place a branch, felled tree, or bar horizontally over the ground. Tie your snare to the bar. Create barriers to force rabbits towards your trap.