Trip wire

A DIY trip wire alarm is any type of cordage connected to something that makes noise, alerting you to the presence of an intruder.

How to Make a Tripwire via wikiHow.com

War Wolf Ordnance N/A for sale from War Wolf Ordnance.

The Sentry Alarm Mines Trip Wire Alarm can be used to protect individual items or large areas with just a trip wire or string...

One man created a trip-wire alarm out of just a few items found in his junk drawer, and when triggered it can set stuff on fire!

Safeguard and protect your home with these booby traps. Intruders won't know what hit them if they try to break in. Stay safe!

If you're camping or buggin out it only makes sense to setup a perimeter. Who doesn't appreciate a good night of sleep. This isn't just a "post-collapse" idea. We've all heard horror stories of bears ransacking campsites while campers are present. Picking up a few magnetic battery operated widow alarms and attaching them to trip wire could mean you have early warning of an intruder in your campsite. And if it's just a wild animal and not a gang of marauders the high pitch 140db alarm…

FithOps™ Camp Safe™ 12 Gauge Perimeter Trip Alarm* Our newest, updated version of our 12 gauge perimeter trip alarm. Made of 6061 Aluminum, this unit utilizes a spring-loaded firing mechanism and a trip trigger. When the trigger pin is disturbed while loaded with a 12 gauge Flash Bang/Training Blank, the unit will discharge. This device is compatible with blanks, adapters, flares and pepper gas depending on situation and requirement. UPC: 850061679130 WARNING: For outdoor use only. Keep away…

American Hacker recently demonstrated how to make a simple trip wire alarm using a clothespin, a LED light, buzzer, AA batteries, and two screws.

"He thought of a native trick he had learned in Uganda. He slid down the tree. He caught hold of a springy young sapling and to it he fastened his hunting knife, with the blade pointing down the trail; with a bit of wild grapevine he tied back the sapling."