Low Cost Alarms and Early Warning Systems for Preppers

by Patrick F – – this is an entry in our non-fiction writing contest.

Alarms are usually one of two types, audio, or visual, although some can be a combination of the two. Alarms are also great resource if used effectively and acted upon when triggered. They allow an extra layer of protection/defense especially if one is short of personnel. Placed effectively alarms can enable a single person to monitor a much larger area than would normally be possible.

While there are many types of alarms and alarm systems available, many are expensive and often require a power source to run and operate. Some systems can even be custom designed and built for an individual’s specific situation and needs. If you have the resources to obtain one of these systems that’s great. I however do not. So I have found and/or made other less expensive, yet still reliable setups. Now please don’t assume these less expensive or homemade setups are useless. I have personally used these on my own property as well as using them in paintball and other more specific simulations, and I assure you they are reliable and effective.

So with that in mind let’s start off with some inexpensive alarms that can be easily purchased and then I will detail some homemade alarm systems. With both I will begin with systems that can be used at a distance and then we can move to shorter range setups. Also I am going to make the assumption that you will be in a position to observe or hear the alarms when they are tripped.

One unit I particularly like is the wireless drive way alarm manufactured by Bunker Hill as well as others. These units run on batteries and usually cost around twenty dollars or less. The sensor unit takes a nine volt while the receiver unit takes three C Batteries. Range for this unit is listed at 400 ft. with both of the units being weatherproof. Range is variable depending upon terrain although I have used these units at several hundred feet both in sight and out of the line of sight.

Beside the advantages of the unit being wireless and weatherproof, they also work well at night and during the day. Also since the sensor and receiver are two separate units, anyone tripping or activating the sensor does not know that they have d0one so as the signal is sent to the receiver.

Although the sensor unit usually comes in white it can easily be spray painted to allow for better concealment. Although this next piece of advice is most likely unnecessary I add it just in case. When painting be sure to tape over the motion sensor before painting so that you don’t block the sensors functionality, and of course also remember to remove the tape afterwards to let the unit function properly.

Additionally the box set, of one sensor unit and one receiver, function together on one channel which is often listed on the box and/or the units themselves. The advantage of this is that one is able to buy different unit with different channels for use in covering separate approach routes. For example one unit (on channel 9) could be located on the driveway while another unit on another channel (on channel 17) could be placed on a walkway or trail. Depending on which alarm sounds, you would know which approach route the intruder was taking.

Another advantage I have often found useful is that the sensor unit is set off every time someone passes it. This allows anyone with the receiver unit to count how many intruders are approaching by that route.

I have only two drawbacks that I have experienced with these units. The first is when the receiver is first turned on it beeps to inform you that is on and active. This is normal and only happens when the unit is first turned on. So be sure to set up these units and have them on in advance of any needed situation.

The second is that one needs to understand that the sensor will pick up anything that passes within its range. This can be animals as well as humans depending on sensor placement.
On the positive side these units are compact and can easily be deployed quickly as needed in almost any location or situation. I have often used them when camping for a reliable early warning system. Also I have had the units at my home run continually for a minimum of six months straight before a battery change was needed.

Another type of alarm that I have purchased and use regularly is the battery operated outdoor wireless motion sensor light. There are several companies that manufacture these although I have only used Mr. Beams brand. These units are almost all strictly visual alarms in which the light comes on when anything gets within range and triggers the motion sensor.

By being battery operated (usually three C Batteries) they can be placed anywhere, and the light they put out can be seen from a good distance away. Most also have a time setting for how long the light remains on usually as short as 30 seconds up to 10 minutes.

Some of the disadvantages of these units will be obvious. Such as requiring batteries, although how often they need replacing is dependent on often they are tripped and how long the light stays on. Another is although they light up once tripped allowing you be alerted and possibly to also see the intruder, anyone who activated it will also know. Finally since it is a light that activates, the unit’s effectiveness is seriously reduced during daylight hours. Along with that is the fact that most of these units have a sensor that keeps them from operating during the day when the sun is out. Yet even with these disadvantages I have found these units to be effective if properly placed.

Another type of alarm that I have purchased involves some type of motion sensor located in garden statuary. These could be visual in that they light up or audible in that they make various noises. They come in various styles and types; from flowers to animals. I have even seen some that were made to look like fake rocks. One of my favorites was a frog that croaked when someone passed within sensor range. Some, like said, were made to function during the day or at night; so if you’re considering purchasing one of these try to get one that will work during the day as well as at night.

Some advantages to these are that some are solar powered, so they need little maintenance and are almost always ready. Another is that they can be placed in more open locations, even inside homes, requiring little concealment. This is advantageous in the event that an intruder activates the unit it doesn’t necessarily mean that they are aware of its significance as an alarm.
The major disadvantage is that they need to be placed somewhat close for an observer to see or hear them clearly. Although some, like my frog croak, can be heard at a distance it is still closer than one would like, especially if one is hoping to be alerted in advance.

Wireless widow alarms are yet another inexpensive system available for purchase at most hardware or retail stores. While specifically designed for use on windows, with a little imagination they can be adapted for other locations. Constructed of two pieces, they are designed to alarm when the pieces are separated, like when a window is opened. Knowing this, with a little imagination, you can easily adapt the unit for use in other locations. Although small they do emit a loud alarm.

The major disadvantage of these small units is that once activated, or separated, the unit will continue to sound until manually turned off or the pieces placed together again. This of course requires that someone to physically do this task. Not the ideal situation if you are still dealing with intruders.

The other type of widow alarm operates by “hearing” glass break and emitting an alarm. I feel that this is a major drawback for two reasons: one most people would hear any glass breaking and two if an intruder is breaking the glass they are already breaking in. These are the major manufactured units that I have purchased and used effectively as early warning and alarm systems.

Now let me talk about some effective and often inexpensive homemade systems, again first discussing alarms that will work or be heard/seen at a distance and then moving closer. Once again I am going to make the assumption that you will be in a position to observe or hear the alarms when they are tripped.

Please note that the following alarms I will describe to you are single use systems unlike most of the purchased alarms discussed above. This means that they will alarm once and then they need to be reset manually to be used again. Although this may seem a drawback at first, if they successfully alert you in advance of danger or intruders then they have fulfilled their purpose. Also most of these systems when set off will alert the intruder to the fact that they have set off some type of alarm or early warning system.

Let’s start with Rat Traps. Yes, you read that right Rat Traps.

With a little modification rat traps can be effectively used as an alarm system in a variety of ways. I must warn you though when using rat traps they are very sensitive as well as somewhat dangerous as they have the strength to easily break a finger or two. So use extra caution when setting. As a safety suggestion, attach the trip line to the trap trigger prior to arming the trap.

When using and setting rat traps I prefer to use thread as the trip or trigger line, rather than wire or fish line. Wire I find is too stiff, while fish line is often hard to work with, especially when tying knots. Thread is easy to use and easily strong enough to act as the trip line. If you feel you need to use something stronger you can also use upholstery thread. The thread has the advantage of being hard to see, or find before and after the trap has tripped, especially at night.

If you don’t believe that thread is strong enough to act as a trip line to trigger a Rat Trap, try it for yourself. I assure you that it doesn’t take much to trigger a Rat Trap. Also while you’re at it, set one and then trip it with a stick or something similar. You will see (hear) that when the trap goes off it is sufficiently loud enough to hear and distinctive, even at some distance, and especially on a quiet night.

There are many ways to set/secure the rat trap, limited only by your imagination. One of the best I have found is to attach the rat trap to a stick, or tent stake. Then you can stick the trap in the ground, which helps keep it secure while you run the trip/trigger line across the designated trail/path.

For use as a visual alarm, try attaching a light stick better known as a glow stick, to the trap. When triggered the rat trap is strong enough to break the internal capsule and activate the light stick. As an added benefit there are many types of light sticks in many different colors and sizes. Separate colors can be used to mark distances from the triggered traps to one’s position. Also available are Infrared glow sticks, which cannot be seen by the naked eye but can be seen with Infrared or Night Vision devices. My personal favorite is the Ultra High Intensity orange five minute glow stick. These are visible at a good distance and effectively light up a good area around the trap revealing any intruders.

Another easy to use alarm system makes use of pull string fireworks or pull string poppers. These are also sold under the name pull string perimeter alarms. They are relatively cheap and come twelve poppers to a box. Basically these are small firecrackers but are not under restricted shipping, so they can be purchased and shipped by mail.

How these poppers work is when the string, which comes out of both ends, is pulled it creates friction inside the popper which sets off the small amount of gunpowder inside the popper itself. To use these effectively one will need to attach a longer string or better yet thread to the popper as the original strings are too short for most uses. The best way to use these is to attach the thread to the string on one end and anchor this end to a secure location. Then with thread attached to the other end string, run this as a trip line across the trail and secure it to an anchor. When setting these, the tighter or tenser the trip line/string is the better, although they will still work if somewhat slack, just not as well. They are set off when an intruder walks through the trip line pulling on the popper’s string and setting it off.

For added security I would often place two or more of these popper alarms close to one another on the same trail. This is because due to the uncontrolled manufacture of the poppers they sometimes fail to go off or pop. By placing several on the same trail one increases the odds of the poppers working as designed.
Another nice place to locate these popper alarms is on a door. Simply attach one end of the popper to the door knob and the other end to the doorframe. When someone opens the door the popper will go off alerting you.

The major drawback of these string poppers is that they are only made from cardboard and paper and so are easily affected by the weather. Wrapping the popper with a small amount of dark duct tape helps keep them somewhat dry. However be careful not to accidentally duct tape the strings, as this will render the popper useless. Also the original strings that are attached to the poppers are white and will need a little camouflage help.

Now let’s discuss using trash as an alarm system. Yep, that’s right trash or more specifically empty soda, beer and/ or other aluminum cans. Don’t discount this system because of its simplicity. Empty cans, filled with small rocks or pebbles were often used and are sometimes still used in combat situations attached to concertina wire in defense situations. Enemy personal would often end up rattling the cans as they tried to get through the wire, thereby alerting the defenders.

So the simplest system is placing some small rocks or pebbles inside the empty can, attaching thread to the pull tab. Secure the end of the trip line thread and then place the can on the other side of the trail. Preferably on something raised up, so that when the intruder hits the line the can will fall and rattle. The can will still rattle if on the ground, but I find it better if on some type of raised surface. Placing the can in a small tree or bush with the line running down diagonally across the rail also works.

A great advantage to this “can” alarm system is that the intruder may assume they have accidentally kicked a can rather than tripping some type of alarm.
Experiment in advance and see what works best for your specific application and terrain.

A nice one that I learned from some good friends is to connect two cans with thread and then hang them from tree branches. One can on one side of the trail and the other on the opposite side of the trail. This can be placed at any height with the trip line across the trail. When an intruder walks into the line the cans will rattle.

Finally one of my favorites which may seem silly but it has always worked for me when placed properly is the use of a whoopee cushion as an alarm. A dark colored whoopee cushion works best, but the lighter colored ones can easily be spray painted.

Placement is the most important part of this alarm, because in order to operate effectively the whoopee cushion need to be on a hard surface or hard ground. Also you need to study the area and determine approximately where someone walking along would put their foot. If you’re inventive you can alter the terrain in a way to make someone place their foot where you want them to. This is where you would place the whoopee cushion and cover it with some debris. Then when stepped on the cushion will expel its contained air and alarm you to someone coming. I can assure you that the sound from this alarm is sufficiently loud as well as being distinctive.

Well that’s it for now; there are some easily affordable alarm/early warning systems for you to experiment with if interested. If you can afford and maintain better systems please feel free to do so. I just wanted to offer everyone some alternative systems.

As with any alarm system redundancy often adds an extra layer of protection. I would recommend using several different types of alarms with backups to be sure that you have enough warning in advance, in the event one system fails.

Also understand that if an intruder manages to detect or trip one alarm then they will be wary of the possibility of others in the area. This could be either good or bad depending on your intent.

Experiment and play with these alarms now while you have the time, before they are needed. If you come up with more ideas on some inexpensive and easy alarms or early warning devices please write them up and send them in for all of us to try and have in our toolbox.

Further Reading

Prizes For This Round (Ends on June 7, 2017) In Our Non-Fiction Writing Contest Include…

First Prize a $999 value:

  1. Numanna Organic Family Pack Bucket a $399 value from LPC Survival Ltd.
  2. CampingSurvival Gear Pack a $400 value from Camping Survival.com.
  3. A $200 gift certificate of prepper books from Prepper Press.

Second Prize a $650+ value:

  1. A case of .308 ammo or $300 off Ammo selection of your choice from LuckyGunner.
  2. A Wonder Junior Deluxe Hand Mill with the Masa/Nut Butter Auger, Drill Bit Attachment, and Bicycle Sprocket Kit a $325 value from ChefBrad.com

Third Prize a $310+ value:

  1. $300 gift certificate from GunMag Warehouse.
  2. A copy of The Prepper’s Guide to Surviving the End of the World, as We Know It: Gear, Skills, and Related Know-How


  1. JP in MT says:

    Due to the fact we are still “in town” we went with a conventional alarm system. One for the house and a second for the detached garage.

    There is a monthly monitoring fee, but I got the system installed at a very low cost.

  2. Listening to what is going on outside or at a distance is helpful. A good set up with a microphone and preamp / amp that makes it sound like you are standing outside will give you a time advantage hearing things like approaching vehicles leaves crunching under feet.


  3. Halfway Homesteader says:

    Living out in the sticks, I have made good use of the Bunker Hill Driveway Alarms you mentioned. They work well, and can be placed on any avenue of approach. They are easily set off my deer or other game. I also like Bunker Hills 6 camera security DVR system. It’s wireless, thus relying on grid power, but allows me anytime access to view all parts of my property, from the back door to the barn door. It’s hardly HD quality, but for the price (around $200), it can’t be beat

    • I’ve had a couple <harbor Freight driveway alarms seemingly identical to the Bunker Hill. The first one didn't last very long out in the rain, even though I thoroughly wrapped it in electrical tape. The second one has lasted a couple years mounted on the house up under the eaves. Weather resistant is not waterproof.

  4. So what’s wrong with some fishing line and a bell?
    It doesn’t need batteries, an EMP can shut it down, it’s not subject to corrosion or lightning strikes and you might even find out what kind of wildlife is available to eat after the big crash.

    • Nothing wrong with fishing line if you can tie a knot in it properly.
      Another thing you can do is use a whole spool of fish line and make a giant jumble out of it with bells attached. Place the whole mess on a trail (almost invisible to see) and when someone stumbles into it they will get tangled up in it. It will take them time to get untangled and they will continually jingle the bells while trying.

    • Jesse Mathewson says:

      Jay, nothing, I keep 300 yards of 40 lb test clear fishing line specifically for this 🙂 but hey, layers and all 🙂

  5. Packy Trucker says:

    Best alarm system I’ve found is the Chamberlain. It handles up to 4 sensors. Transmits half a mile. Uses AA batteries. No lousy 9 volt. Sensor works up to 30 feet. Batteries in sensors last 2 years. Receiver uses 110 volt with battery backup. $50 on Amazon.

  6. I have outside & inside motion detectors for alarms & lights. Camera systems with microphones but the best system are dogs. Not only can they alert you but they can run off or even kill an intruder.

    The best defense is rings of defense alarms and physical barriers !!!

  7. tommy2rs says:

    I use the Dakota alert system. Currently have 4 sensors around the property. I’ve also got sentry mines (uses nail gun blanks) though they have gotten expensive in recent years. Also have motion detector lights (the ones on the house are hard wired so we can turn them off when the weather starts setting them off, the garden ones are led and solar powered), including out in the garden. Lol…I want the garden targets lit up.

  8. A lot of helpful information. I guess pick and choose what works best for us. Thank you

  9. We have the Dakota Alerts since our front gate is a half mile from the house. The first one is about 150 yards before the gate under the county road (dirt) with the transmitter in a bush. I dug the trench with a backhoe. This one is a vehicle sensor and is set to detect something as small as an ATV.

    The second sensor is an IR sensor that detects movement about 50 yards in front of the gate.

    Both these sensors are set up broadcast “Alert Zone One”

    The next sensor is IR and about 100 yards past the gate. It broadcasts “Alert Zone Two” in a male voice. The next one is about 350 yards past that and also broadcast’s “Alert Zone Two” in a female voice. If I hear Alert Zone One then shortly after hear Alert Zone Two, I know someone has gone past the gate.

    I keep five personal alarms in the GHB. These are very small with a pin and a string. When you pull the pin it emits a 120 Db siren and a very bright strobe light. They make very good trip wire alarms. They use a standard 9 volt battery. Not only do you hear them, but you can see the location of the intruder from the strobe light.

    These units are about $10.00 on Amazon or Ebay.


  10. Chuck,
    I’ve constructed my own alarm systems from various parts; but, I’m interested in the units you listed from Bunker Hill. They look to be identical to the ones offered by Harbor Freight that I have been considering getting to test.
    For outdoor motion lighting I have some of the Harbor Freight solar powered versions; but, one of them is on almost continuously while the other appears to work OK.
    I will be looking at yours.
    I’ve seen the frog and a bird that activate when you pass them; but, always considered them as a novelty. I may rethink their use and add a few to the system here.
    I have several versions of the window alarms that are wired units; but, they require one to lift the window to activate. I would be interested if anyone has looked at inexpensive glass break sensors or alarms.
    Instead of a rat or mouse trap you can sandwich two pieces of aluminum foil with cardboard between them as an insulator in a wooden sprint type clothes pin. When the trip line is triggered, the cardboard is removed and closes the alarm switch. Instead of thread, unwaxed dental floss is inexpensive and amazingly tough.
    Using a full sized aspirin instead of the cardboard can also be used as a water (as in flooding basement) detector.
    Finally, there are now a lot of inexpensive digital cameras that can be connected wirelessly to your computer that can run motion sensing software. You can generally set the detection range to ignore the cat or dog or when doing automated overwatch out of a window, to ignore the motion of trees and bushes blowing in the breeze.

    • Dental floss is great but as far as I know is only in white. For outside use you may need to camo or color it. This is why I prefer upholstery thread. It comes in many colors so you can use the one you need that matches the terrain and environment where your placing the alarm.

  11. Jesse Mathewson says:

    Awesome article Patrick!

    In my trailer/15′ • 5′ single axle motorcycle trailer slightly added too for large bugout purposes and bike trailer – I have a series of solar powered wireless spotlights and driveway motion style detectors – I always use them when camping, as we do not generally camp where others are- and in many cases it’s just my kids and I or family alone- force projection through early detection…:)

  12. I like early warning systems and have used cans for bear alarms while in hunting camp but at home we use the German Shepard brand he not only is a early warning system but stops most people in there tracks and if he don’t work his sister will back him up.

    • Agree we have Mastiffs here for security, but a lot of people don’t use their dogs correctly. Ours are house dogs . Many people have them in pens away from the home. When they end up barking a lot people start ignoring them. Dogs aren’t much good locked in a pen/run separated from the house.

  13. Tres Perros says:

    We are in a pretty decent neighborhood, nothing gated, but lots averaging a little under 2 acres. Plenty of trees and wildlife roaming all hours. After 18 years we have only had two known attempts to do God knows what and a couple of others that are thought to have been something nefarious but no real proof. We have chosen a slightly different approach to home and family security. First and foremost if the worst happens (a breach of household door, window, etc.) all our family has a fully loaded 870 at hand. All have been shooting for many, many years despite the age of some. All have been properly trained in defensive shotgun from inside the house. DEFENSIVE. We are not looking for a fight, in fact we pray it never ever happens to anyone we know and love. So we have used a security system called Tres Peros (three dogs). One very large male with an awful sounding bark. From behind the door it sounds as though he wants to eat your throat. I like that. And the two girls, both Healers. Our set up…. each night one of the girls stays outside the front door on a 50 ft steel cable. This keeps her from running away after some potential perp or wildlife critter. The big boy has couch duty nightly. The other girl is in dad’s bedroom with the door closed. Mon, Wed, Fri our Jess pulls night sentry duty. Tue, Thur, Sat Abby does her job. Sun night we all play inside and the big boy gets to sleep in the bedroom. Anyone getting too close to our house (front or back) gets the night sentry going nuts! This of course gets the two inside getting a bit excited. And this of course gives dad and all inside PLENTY of time to get Mr. Shotty ready if needed. If the canine mayhem doesn’t calm down in a minute or two, the third dog in the bedroom gets let out to join in the chaos that the bad guys hear coming from inside the house. If all dogs and perimeter gets breached they will face a barrage of 4 or more 870’s trained in their direction. This has worked well for us for many years and we sleep very well at night. YMMV. Is it perfect? Not by a long shot. Alert alarms and motion detectors would literally be going off ALL the time in my location. And those that say the night sentry could be compromised I say TRUE. But if that were to happen the two inside would still be going crazy and if the two inside are going ape sh*t and nothing from the girl outside, then we know the probable situation don’t we. And those that question mother nature’s warning systems take one or two camping some night. Nothing gets close with out their alerting on it. The more dogs the better for your home ‘system’. We have found three is affordable and very, very effective as a warning device.

  14. Christian Gains says:

    The “aluminum can tripwire” alarm can be utilized IN your house as well…

    You simply attach one end of your “wire”, [thread or fishing line], to a window or door, (whichever you want secured), then (having screwed “eye hooks” in the wall, several feet apart, crossing the room, or traveling along a wall, TO your room, (best is have the hooks high, near the roof), and the last two hooks are above your bed, with the cans, [filled with small pebbles], just above your head.

    Make the wire tight, so that the slightest opening of the window or door will pull the wire, which will shake the cans, {2 or 3}.

    You’ll need an EYE-HOOK on the upper, inside corner of the door, or window, AND an eye-hook just above and directly over that door / window eye-hook. That way, the slightest opening of either, WILL shake the cans.

    Also, arrange the cans, (use a clothes hanger), hanging down about 2 in., but also, an inch apart, & about 21/2 in. OFF of the wall. Also, have the “wire” tied to the clothes hanger’s handle, so that the pulling of the wire will pull the hanger UP, and cause the cans to rattle.

    Be SURE that your “wire” is tightly bound at the DOOR, AND STRAIGHT UP to the eye-hook, so that, even the door opening SLIGHTLY, (preferably no more than an inch), will STILL pull the cans up! (an added noise maker is to have the cans sitting on a thin ledge, so that when the pull comes, they’ll all fall off of the ledge, AND hit each other, causing even MORE noise; {for SOUND sleepers! lol}

    • Christian Gains,

      Be SURE that your “wire” is tightly bound at the DOOR, AND STRAIGHT UP to the eye-hook, so that, even the door opening SLIGHTLY, (preferably no more than an inch), will STILL pull the cans up!

      This description just reminded me of another inexpensive trip wire type of alarm. Often called the personal panic alarm. Generally a small gadget costing $10-15; but, when you pull the pin it screeches out at 100+ dB and would work well for your application.
      One of the classes I teach is called Refuse to be a victim and I was introduced to this device when I trained for that class. Another use for the device is for women (or men I suspect) who carry a purse, satchel, briefcase or other tote. When attached firmly to the tote and the pull line to your person (like your belt) you’re ready to go.. If someone snatches your package and starts running with it, they are also carrying a device that’s screaming at 100+ decibels, and if you yell that someone has stolen your tote, they cannot simply fade into the crowd unnoticed.

  15. Illini Warrior says:

    plenty of UTubes on using mouse traps and kid’s snap gun caps for a tripwire alarm – plenty loud and waterproof – “ammo” is cheap ….

  16. Awesome stuff folks . please keep those ideas coming. As for my home system we have three Mastiffs as added security. Which are great.

Before commenting, please read my Comments Policy - thanks!

Speak Your Mind