How to Make a Tripwire

Creating a Tripwire Bang Alarm

Gather your materials. You'll need fishing line, a mouse trap, ring caps, tent pegs, nails, screws, and rubber bands.

Screw the mousetrap to the tent peg. Use a drill to screw through the mousetrap onto the top half of the tent peg. Use a screwdriver and wood screws to screw them together.

Screw through the trap behind bait pedal. The bait pedal is the metal rectangle part that the mouse steps on to release the trap. Drill a hole behind it through the mouse trap. You'll tie a knot over the bait pedal later.

Cut out the pop caps. If your pop caps are in a ring, cut out individual ones. One should fit over a small nail head. Instead of pop caps, you can use a glow stick.

Release the trap several times. You need to see where it's hitting the wood when it releases.

Hammer in two nails. Where the bow hits the wood along the sides, drill a small hole on each side. Hammer a nail in each hole. The head of the nail should face the bow as it swings down. In other words, the bow should come down and hit the nail on the head when the trap releases. If you're using a glow stick, drill four holes. Tie the glow stick on so that the bow hits it when the trap releases.

Paint the tent pegs and the mouse trap. If you want to camouflage your trap, paint the mousetrap and the pegs to match the surroundings. You can also paint the tent pegs before you attach the mousetrap.

Tie the fishing line to the other tent peg. Securely tie the line to the other tent peg. Hammer the peg into the ground.

Run the fishing line to the bait peg. Make sure the wire is taut across the path. Run it into the back of the trap to the front, and tie it to the bait pedal.

Use a rubber band. Rubber band the tripwire onto the peg and the mousetrap. The rubber band will secure the tripwire.

Arm the mouse trap. Add a pop cap to each nail head. Pull the bow down to arm the trap.

Leave it to secure your campground or area. When the tripwire is triggered, the mousetrap will hit the pop caps, making a loud bang. It will tell if a person is walking in the area. If you used a glow stick, the glow stick will light up when hit.

Making a Tripwire Out of a Water Bottle

Clean out a sturdy water bottle. A standard 20 or 24 ounce bottle is fine for this purpose.

Cut the water bottle in half. Mark the middle of the bottle. Use a hacksaw or scissors to cut the bottle in half. You'll use the top half of the bottle for this trap.

Smooth out the edges. Use sandpaper to smooth the edge of the bottle. Also, tape over the edges with duct tape.

Cut the small end off of a balloon. Stretch the rest of the balloon over the bottle opening. It doesn't have to go over all the edges. It just needs to stretch across the middle in a single band.

Cut out a small piece of wood. Part of a Popsicle stick would work well for this project. It should be shorter than the balloon band is wide. Round the edges.

Add hot glue and a string. Place hot glue on the piece of wood. Glue down a strong piece of string across the wood.

Line up the wood on the balloon. The balloon should go across the width of the balloon band. Let the strings go down on either side. Pull the ends through the mouth of the bottle, going from the inside of the bottle to the outside.

Tie a knot in the thread. Tie a knot in the thread that rests partway down the inside of the bottle.

Attach stakes. Use three pieces of sharp wood that are longer than the half bottle. Glue or tape them them on to each side. They should stick out past the mouth but not out past the other end. You'll use these to stick the tripwire in the ground.

Create the trigger. Use a small piece of wood that barely reaches across the mouth of the bottle. Tie a long string to the end.

Create the tripwire. Tie the other end of the string to the top of a small stake. A Popsicle stick will work for this part as well.

Pull out the knot through the mouth of the bottle. Place the small stick under the knot. Angle the wood across the mouth of the bottle.

Set the bottle in the ground. Push the stakes in the ground, being careful not to pull the trigger. To truly prank your friends, you need to disguise the trap somehow. However, you can't hide the top of the bottle, as that will release your trap.

Stretch out the string. Stretch the string out to the stake. Shove the stake in the ground.

Add flour to the trap. Tip flour or water into the balloon trap.

Wait for someone to trip the wire. When the wire is tripped, the balloon will throw the flour or water into the air, getting it all over your friend.

Making a Doorway Buzz Alarm with a Tripwire

Gather your materials. You'll need a clothespin, an electronic buzzer, a lithium battery, two-sided adhesive pads, a twist tie, fishing line, and a small piece of copper tape.

Keep the clothespin open. Use the twist tie to squeeze the ends together. You want to hold the clothespin open.

Wrap the copper tape around one of the open ends. Use the copper tape to cover one of the open ends, wrapping it around the top. Smooth it down to the wood.

Attach the red wire. Use the adhesive pad. Use one sticky side to stick the red wire to the copper on the top of the clothespin.

Stick the buzzer down. Use the other sticky side to stick the buzzer to the top of the clothespin.

Stick the black wire down. Place the stick pad on the inside of the clothespin mouth. Put it on the side without the copper. Stick the black wire to the top of it.

Place the battery on top of the black wire. With the negative side towards the black wire, stick it down to the black wire. Center the wire on the battery.

Make a hole in a small piece of cardboard. The cardboard should be thin and about an inch wide and long. Poke a hole with a needle.

Tie a string in the hole in the cardboard. Use fishing wire. Tie a string around the hole.

Place the cardboard inside the clothespin mouth. Release the twist tie at the back of the clothespin. The string side should be near the mouth of the clothespin. Pull out the cardboard to test the clothespin. See if it buzzes. Place the cardboard back inside the mouth.

Attach the tripwire to the wall. Use adhesive pads to stick up the clothespin. Run the tripwire across the doorway. Tape it up on the other side of the doorway. Make sure it's taut but not taut enough to pull out the cardboard without much pressure.

Let someone trip the alarm. When someone crosses the tripwire, it pulls out the cardboard. The clothespin will close, connecting the circuit. The buzzer will sound.