In a previous article, I wrote about how to harden one’s home against intruders, which detailed how to make a home far more difficult to enter.
In these tumultuous times, we have seen too many examples of riots, looting, and unrest sweep across the globe. Whether it be civil unrest, protests turned riots, or pandemic related panic many events can see the criminal element and looters at your property line.
In these cases, sometimes a good offense is the best defense, and having an early warning system in place can and will be the deciding factor in the security of your home. With a few items from around the house, you can build some tripwire triggers that will act as an early warning system to alert you to where intruders are entering your property.
Related: How to Harden Your Home Against Intruders
The Legal Stuff
What I am describing is what‘s commonly known as a ‘booby trap’. While these early warning systems are not designed to inflict any harm to those who trigger them, it is up to you to research the rules, regulations, and laws regarding such devices in your area.
These two traps, whose construction I will detail, have similar purposes but they achieve them in different ways.
The first is very simple, a rat trap, paracord, zap straps, and a glowstick is all you will need to be alerted to where the bad guys are. This method has a significant issue which is that the only way you will know that the trap is triggered is to be looking at it, this means someone in the house has to be on watch looking towards the trap to see it get triggered.
The second is not overly complex but requires some electronic components and a little bit of experimentation. The idea behind it is that when the trap is triggered a LED light will alert you to an intruder.
The Rat Trap
The first trap I will describe is by far the simplest and requires minimal equipment and skills to construct. It works by placing a glowstick in such a way that when a rat trap is triggered the spring arm of the trap snaps closed on the glowstick shattering the vial inside of the stick. The trap is triggered by a tripwire of paracord, bank line, or wire.
- 1 – Rat Trap
- 1 – Glowstick
- Zap straps
- Drill and drill bit
Step One – Determine where the glowstick is going to mount on the rat trap. Then drill holes on either side of the glowstick to accommodate a zap strap.
Step Two – Mount the glowstick using a zap strap making sure that the glass vial inside will be broken by the spring arm when the trap is triggered.
Step Three – Attach paracord to the trigger of the trap. You may want to modify the trigger to make it easier to attach the cordage.
Step Four – Mount the trap in a suitable location then run the paracord to form a tripwire. Do not securely tie it off yet since you have yet to set the trap.
Step Five – Set the trap as normal and very carefully adjust the tripwire keeping in mind that because of how sensitive the trigger mechanism is the tripwire will not be taut. Also, the longer the tripwire the heavier the line and in turn, the looser it will have to be. It is best to keep these lines short or made from lightweight materials.
The LED Trap
This trap requires a few electronic components which you can easily find or scavenge from old electronics. For this article, I have shown the simple circuit on a breadboard, but you will want to assemble the components more permanently through soldering.
#1. An important point of note is that I have not specified a value for the resistor in this circuit. The reason for this is that the longer the run of wire you need to use the greater the resistance that wire will provide the circuit and in turn, there will be an associated voltage drop. When constructing this circuit, test it using the full lengths of wire to ensure that the LED’s light to your satisfaction. Do this before placing the traps in position.
#2. Use a separate power source for each trigger. You may find that it is better to use higher voltage batteries for this project depending on how long the runs of wire are.
#3. One advantage of this trigger is that you can place the LED’s on a cardboard map of the property.
In this way, you will have a visual representation of exactly where the incursion is taking place.
- Wooden or plastic clothespin
- Length of two lead insulated wire of a thin gauge. It needs to be long enough to run from your tripwire location to where you are going to install your warning light.
- LED bulb
- 9-volt battery connector
- 9-volt battery
- Electrical tape
- Metal tape
First Step – Wrap the jaws of the clothespin with metal tape so that they are wrapped all around. This is what completes the circuit so make sure that the only place the two sides touch is where the jaws of the clothespin meet.
Second Step– Split and strip the ends of the two-lead wire then attach one lead to the outside of one of the jaws of the clothespin with a piece of electrical tape. Repeat for the other side and secure the wire to the clothespin further with a wrap of tape.
Third Step – Construct the circuit by connecting the positive of the battery to the resistor then to the anode of the LED.
Then – Split and strip the other end of the twin lead wire and connect one of them to the negative terminal and the other to the free lead of the LED.
Step Five – Test the circuit and the brightness of the LED. You may want to change the resistor value to increase the LED brightness.
Step Six – Use a zip tie that has been fashioned into a loop as a non-conductive trigger for the tripwire.
Step Seven – Place the trigger and set the tripwire. I like to use a nail or screw through the hollow part of the clothespin spring to secure it.
This trigger can also be placed on doorways as well by securing the zip tie to the door and the trigger to the door frame.
These devices are useless if you place them where no one would walk. The best way to figure out where to set these devices is to approach your house from the perspective of someone who would want to break in. Look for areas that provide good cover from view and identify avenues of ingress that a looter or other criminal would likely use.
If you place them in areas that are often used by yourself or your family be sure that everyone is very aware of the locations of each trap. Also, be aware of any possible four-legged intruders as well because you may have to adjust the heights of the tripwires to avoid false alarms.
Related: How To Install A Trip Wire Alarm On Your Property
The advantage of early warning systems such as these is that in a lot of instances the materials for these are laying around the garage or homestead.
The rat trap versions are good for placing at longer distances and if you have access to night vision and IR glowsticks they can be an almost invisible version of a trip flare.
While the LED version takes a lot of experimentation and a bit of skill it can in a lot of ways be a better early warning system because it only requires one person to be aware of and looking at one set of lights rather than trying to keep watch of several glowstick traps.
You may also like:
5 Traps to Catch Animals While You Sleep
How To Make Your House Invisible To Looters (Video)
No Gas, No Electricity… How To Cook Indoors Without Smoke
6 Reliable “Pocket” Revolvers For Off-grid Defense
Spider Hole Tactics to Defend Against Looters
Really good info. The moon shinners use mason jars tied close together for there Bobby trap.
The legal stuff. No trespassing. Means if you enter you might be subject to a Bobby trap. Lol.
I like to be better prepped than soooo much improvising – but still endorse the DIY ….
found the two part magnetic window/door alarms to be the eaziest to improvise for field deployment trip alarms >>> one hell of a constant squawk once tripped …
definitely recommend some ready to deploy stakes with whatever alarms you choose – ditto on camo paint to disguise everything
I look and read your articles you post. Makes me think of my childhood. Right now I am working with a plant
rosemary for thinning hair. I have one of the Lost Ways
books. Just cannot afford the cost of another. Thank you
for the one that is free.
Why would you want to thin your hair ?
The recipe is to help thinning hair to be thicker, duh
sorry for the duh.
There are a whole of string triggered things one can come up with once the gloves come off society……none of which I’d post details about on a website. Make sure you have plenty of flat black high test fishing line around.
For after the lights go out I like punji sticks and punji pits. Even food cans cut with spikes on the top and scattered about on the ground are effective. You can cut the lids into a point and fasten them to the top boards of a privacy fence to make climbing over the fence a memorable experience.
Lowes, and I am sure Home Depot too, sells short lengths of rebar. a 1/4″ diameter rebar 24″ long makes a perfect punji stick when sharpened on both ends, one to stick in the ground and one to point upwards.
All of this, of course, is for that period when Rule of Law has vanished into the dusty days of yore — or yesteryear as the Long Ranger on radio used to say.
You want to leave a path leading to your shelter so that you can approach in a zig zag fashion. You also want it to funnel into your direct field of fire.
For a more westernized barrier, Coleman’s Military Surplus was selling a pallet load of razor wire for a nominal price. It is a bit of an overload for the average suburban homeowner, but for someone with a bit of property it is a good buy in my opinion. A pallet load would certainly create an impenetrable barrier around my suburban home. One might not even be able to see the house for the razor wire. Of course, that would mean that I would have to dig an underground escape route to be able to leave the house. I wonder if the neighbor in back of me would mind if my tunnel opened out into his backyard?
LCC: I have razor wire stored away if the time comes that it will need to be deployed. Enough to cover all entrances to house and property. With a hidden trip wire arrangement in front of the razor wire it would be a nasty experience to fall face first into.
My wife and I took a trip to Mexico a few years back. As we were walking the streets of San Miguel (the big “town” on Cozumel), my wife noticed the nice stone walls surrounding the houses. She said, “that glass is very pretty. So many colors!”
The glass was affixed into the cement at the top of the walls. Most came from broken bottles, so it had some thickness to it. The edges were pretty jagged.
“Keeps thieves out, too,” I responded. Then she understood.
They do this in the French Quarter in New Orleans, LA.
same thing in the Philippine islands too!
My wife is from the Philippines. There is it common to have walls topped with broken glass. Of course, a thick mat defeats it. But it stops the casual person from climbing the all.
They do not have to worry about being sued because someone got hurt trying to trespass.
And don’t forget The Shadow, “Who knows what evil lurks in the hearts of men?”
Sounds like the article might have a part 2 discussing ‘illegal methods’, we can all go hog wild describing our fave bobby traps then.
punji sticks are better if you make them hollow and cut the ends at a slant and sharpen them just like a hypodermic needle, human feces or other toxic substance guarantees a very bad day for the intruder. old tube type televisions and computer monitors have a thick glass that is as sharp as a razor when it breaks, i brake mine in a 50 gallon barrel with a removable lid with hole in the top for a rock bar to crush the glass. just cut yourself with a tiny piece and wait a few days to see just how painful it becomes 🙂 i put it where no one has any right to ever be and inside tubes with compressed air propulsion, makes much less noise than anything powder fired. im burying the bodies in buried removable top metal barrels already supplied with caustic chemical to dissolve any thing including the barrels and on property NOT connected to me. i do have some on my property but only for extreme emergency use.
i use 1 inch dia pipe welded into caltrop and sharpened very much like a hypodermic to cut a hole in the tires that happen to be in wrong place at wrong time. and i have delt with retaliation for ruined tires more than 40 years ago, so im not letting anyone retaliate and if SHTF actually happens during my life time, ill leave the bodies on display as a warning to those that might think they can do what they want on MY property. and i have been to prison 3 times so its clear i do NOT care about something being “legal” or not to those in society!
I have Harbor Freight driveway alarms set around. Silent outside they alarm inside the home. Since they just have one sound I set the receivers in dIfferent areas of the home so I can know instantly which alarm is sounding.
I’ve also planted cacti along a fence by dirt side road. As they grow I’ll cut and fill in bare spots. Edible pads and fruit with wicked thorns.
Along another side where there was a path coming into the property I plan to plant black berries. End of path and easy entry from that side. The rear of the property, the owner behind just died so no idea who will be moving in. I may want to harden that direction as well. I can hardly be cited for planting edibles, so for now that is the first line of defence. And it adds to supplies. The driveway monitors were cheap. That’s the only non edible and I must say I’ve surprised a couple of teens in the middle of the night. I was obviously armed and sent them home with a warning.
Dogs can be good alarms too. My little yapper let’s me know when anyone is around 4 legged or 2 legged. Bigger dog that was abandoned here a few yearsago has a silent way of walking guard with me. No barking but protective. I’ve had her stop me from walking between buildings where intruders were. At the time a son was here and we would walk different areas but within calling distance. On one occasion I called to him to close off the other end of that area. Then I addresses the intruders. Told them to leave by the path they came in. Two young men took off like scared rabbits. Ran for the fence. One fell hard and the other kept going. The one who fell was yelling and cussing at his buddy for not helping him. We had a good laugh at their expense. Haven’t had much trouble anymore with intruders. Dog is still here. Neighbor on my property feeds her. She’s protective of the grand kids there. Found out the history on her. A vets PTSD service dog. She took off after he died. From a town 50 miles from here. She picked this place. No wonder she was quiet and protective. That’s the third dog that has adopted me here. All protective from the first. I was newly widowed when the second dog joined me on my daily 4 mile walk. Within minutes my stepson stopped to talk to me and she wouldn’t let him close. (good judge of character) Neighbors said she’d been dropped off near the post office. Dirty, skinny, and hungry so I kept her. Glad for the company too.
I wouldn’t mind another good larger dog. My yapper weighs 10 lb. Loud but no protection beyond her warning barks and growels. I’d like one to train to walk silently with me. I should check out the shelter if I get to the city again. A bigger dog can seem intimidating.
Check out an Akita Rescue Shelter
They are working dogs and thrive on protecting you and your property
The “Dollar Tree” & “Harbor Freight” stores have small (electronic) window-alarms, which – when the circuit is broken by taking away the ‘matching-magnetic block”,…by tripwire,…. will emit a screeching – ear-splitting-siren of sound,…….. almost guaranteed to cause the intruder to die from sudden fright, as well as giving away location,…..and,…… can be heard for up to a mile away! (Tried this one out-myself!),… Low-cost & batteries are replaceable,….as well a re-settable (after finding the missing mag-block). Gotta be set so that ordinary wildlife cannot set them off,….. but if they do,… they’ll never do it twice – because of how LOUD the dang thing is……!!!
I took apart a bunk bed mattress and pulled out all the springs. The larger ones are along the outside borders, the smaller ones (<1 inch) are in the middle. I did this to aggravate squirrels that climb branches to get to the bird feeder. But I also realized that the brown skinned springs are thin enough to allow a foot to separate the rings (think: trip hazard, if laid on the ground, letting grass grow thru it). Plus, any twist of the foot will likely hook the foot into another "round" of the same spring, or even a nearby one.
One smart guy mentioned (if you live in more rural areas) that You don't really want people at your doorstep or window, uninvited, in the middle of the night. If you can, you want people to be deterred "much further out" from your house. How would you approach your own house unseen? Is there a woodsy area near you house?
Even an intentional hole, here and there can trip up the willfulness of an uninvited guest, especially if it causes a sprain. How about a fence with a hedge and weeds along it? That may be a good place for brambles (blackberry, black raspberry, red raspberry). I'm in S/WI I have a hedge with inside of it lots of berries (for food an deterence). In WI the nastiest of trees (when you keep them short) are Locusts (they can have 1+2-inch long sharp needles. One could even plant "itch-rash-pain" weeds along hedges and put a couple of posts in announcing "Beware of Poison Ivy–It can pain you even when it gets on your clothes!" It might look from a distance like a "way to get close", but it might not be worth trying to cross a "weaponized weed patch". And, if you really are nasty you can use your trip alarms to "ratchet up" swatter-branches to snap at trespassers (hopefully not with locust tree branches. Still you also need a No Trespass Sign and poison-ivy/oak, and spiny branches warning, to cover your bases. If you have areas of seasonal hard-pack dry soils, even round river or stream rocks about the size of a huge apple (put your finger tips together and make a circle–that big), and painted black) just laying on hard-pack ground can trip up any night time runner, and some walkers. It could seem odd to a thief to get smacked in the face by a branch that was wedged and somehow it became unwedged when the trespasser stepped on a board of big fallen branch. Then a little ways further to step on a round rock and twist his ankle. And, dammit, if he really did get tore up by brambles at the outskirts of your yard. 3 strikes and one might choose to "get OUT".
Enjoyed that post. Couldn’t help laughing out loud. You and I think alike. I don’t remove poison ivy on my property for pretty much that reason. I’m not allergic to it so can do what I want without consequence. Thistle, is also a good deterrent. I’ve got plenty of it too. I am low on nettles so will have to plant some. Burn, itch and bleed deters many. Goose berries, have some nice thorns plus they are edible. Weeds that have a noxious odor are good just for the after affect. Roll or wade through that and you will walk home because nobody will let you in the swat van for the trip back.
Just a word of caution on setting booby traps, if they can and/or injure someone you will be held liable by the authorities who with our present government will go full tilt on you. That being said, make sure you do a little clean up after the trap is tripped and they will have a harder time proving it. On the LED alert just add a buzzer or siren module so you get an audible alarm because you can overlook an LED just as easily as a glow stick. I used to collect discontinued alarm switches and modules whenever a homeowner upgraded their security so I have what I need. I have used the clothes pin switch and it is a very cheap and easy to deploy method of protecting you from surprises.Tin cans and bottles strung up make a good audible when you deploy them near an entry point. Also, taking the time to construct a maze of sorts to force anyone approaching into choke points that will hamper them and give you more time to react. You want to give them one path to access your property/house. You don’t want them to be able to enter your home from half a dozen different directions.Also, everyone wants a badass vehicle but I recommend a generic vehicle that will blend in with the crowd. So in a city with a thousand cabs make your evacuation vehicle a cab to blend in.
I love the idea of planting lots of blackberries and other things with thorns or brambles…both a nice food source, and also a nice hedge to channel intruders into the only ‘unrestricted’ areas where you want them to try to walk. I’ve never planted gooseberries so had no idea they also have thorns; thanks for the tip!
The glow stick idea is good in other than winter seasons here in the northwest.
I used to keep glow sticks in the company truck just in case they’re needed. However, they will freeze in the winter and when they do; They no longer work.
Of course, if you live where you have mild winters then all the better.
How about some geese to sound the alarm?