When we talk about defending our homes, there are usually two parts involved; passive and active defenses. Active defense are taking up arms and fighting in defense of home and family. This is the ultimate defense, as any passive defensive network can eventually be overcome. But that doesn’t mean that you shouldn’t have passive defenses in place. You should, because they will make it easier for you, when that time to take up arms comes.

Passive defenses are mostly about making it harder for the bad guys to get into your home. To do this, we mostly concentrate on hardening our doors and windows, making them harder to break through. But passive defenses can go much farther than this. Properly done, passive defenses can act as a warning system, shape the battle to come, delay the enemy and even inflict harm on them.

We can basically break our passive defenses down into four different areas. While these will be interrelated and work together as parts of your overall defensives strategy, they each perform specific functions:

  • Hardening your home – Making it hard for them to get in
  • Perimeter defense – Controlling access to your property and shaping the battle
  • Alarms and surveillance – Letting you know who is coming and where they are coming from
  • Booby traps – Slow the enemy advance, causing them to be more cautious, through inflicting injury

I’ve dealt with hardening your home and building a perimeter defense in other articles, so I’m not going to repeat that here; rather, in this article, I want to concentrate on dealing with options to consider for alarm systems and booby traps. The parts of passive defense that receive less attention, or receive the wrong type of attention, even though they can be of a lot of help to the average prepper.

The Legal Mumbo-Jumbo

Before I go any farther, I do need to give you a warning however; that is, booby traps are generally illegal, especially if they have the capability of killing. Essentially you are liable for any damage that they inflict on another person, just as if you had injured them yourself.

While none of us are likely to shed many tears about a criminal being hurt by a booby trap that we created, it would be a tragedy to have a neighborhood child hurt by something we created to defend our home. Children are curious and don’t really recognize things like property lines, so you can be sure that if you lay a minefield in your front yard, some child will find it.

So care must be taken in the use of booby traps, especially in normal times. But if we find ourselves in a post-disaster time, with a breakdown of society, those same booby traps may very well be exactly what you need to have to protect your family.

Granted, a child being hurt by them in such a time would be just as tragic as any other time. So for that reason, any use of booby traps will have to be well thought out and executed, keeping things safe for children. Just keeping them inside your perimeter is not enough, if children can get inside. Rather, you have to make your perimeter impervious to those curious children, if you are going to use any sort of booby traps.

Integrating Your Defenses

Alarms and traps must be integrated into a complete defensive strategy, not used on their own. What good is an alarm going to do you, if attackers are only two seconds away from your door? There has to be something slowing the attackers down, so that when the alarm goes off, you have time to respond.

Likewise, any sort of booby trap is best used in conjunction with other obstacles. Digging a classic pit trap in the middle of your front yard, covering it and expecting the bad guys to fall in really isn’t going to do any good, unless there is something that forces them to go in that direction. Otherwise, they’ll just skirt the trap, possibly without even knowing it is there.

Rather, the place to put that pit trap is in the most likely avenue of approach, with obstacles around it that funnel anyone crossing your yard in that direction. That way, they are almost forced to fall into the trap, unless they know the secret way around it.

Another way to use traps is to back up your other passive defenses. Whether you use s hedge, fence, wall or ditch as your primary perimeter defense, there are ways for people to get around or over them. But if that perimeter is backed up with traps, then anyone who tries to defeat it will very likely find themselves falling right into your trap. By using the two together, you multiply their effectiveness.

The same goes for alarms. Running an alarm all the way around your home is difficult. But if you have a static perimeter defense, you probably don’t need every inch of your perimeter alarmed. Rather, you need any openings, as that’s where the bad guys will probably enter. So in this case, the hedge is helping your alarm be more effective and the alarm is helping your hedge to be more effective.

An Important Planning Point

This brings us to a very important point about how you should create your defenses. That is using psychology to your advantage. Warfare is, after all, a psychological operation. The most effective military commanders throughout history, have been those that understood their men and their enemy the best, using that information to motivate their own men and demoralize the others.

In talking about passive defense, the most important psychological point to remember is that when given an option, people will almost always take the easy way. So, offering them an easy way to get through your perimeter is a fairly sure way to get them to go where you want. If you offer them two equally easy ways, most will go to their right.

On the other hand, if you don’t offer them any obvious way of entering your property, leaving everything equally difficult, you have no way of knowing which way they will use. While you might delay them longer like that, you won’t totally stop them, unless you can devise a totally impermeable barrier.

Chances of accomplishing that are extremely slim, so you’re better off building your defenses with some seemingly weak points for the enemy to exploit. Then, you put your alarms and booby traps in those locations, all but forcing them to either set off an alarm or trap as they enter.

If you are going to use more than one trap, be sure to vary them. Once someone falls for one sort of trap, they are less likely to fall for it again. Chances are that other members of their team won’t fall for it either, as they will learn vicariously by the experience of the one who has been injured. But that can serve to your benefit, as they can become so focused on looking for that same kind of trap, that they don’t see others.

Surveillance & Alarms

Unless you’re going to have that impenetrable passive defense I mentioned a moment ago, you’re going to end up having to defend your home at some point in time. This means knowing when the bad guys are coming, so that you can react.

Some people talk about establishing perimeter guards or setting team members up in a high point to watch for any pending attack. That is effective from the point of view of knowing what’s going on, but an inefficient use of manpower. Survival is an all-encompassing task and if one or two team members are standing guard duty round the clock, that’s going to severely cut the number of people you have available to get work done.

Besides, pulling guard duty is boring. That boredom can cause inattentiveness and even drowsiness. If your guards are visible it sends a signal to others that you probably have some reason to need guards. This could end up inviting attack, and not just any attack, but a well-organized, coordinated attack from a larger group of people. So the presence of guards might actually be counter-productive.

Attackers who see that you have guards posted will also take precautions to keep themselves invisible until the moment of attack. Rather than walking boldly up to your perimeter, they’ll try to keep themselves concealed behind buildings shrubbery, vehicles and fences. They’ll want that element of surprise if they can get it.

But at the same time, you really can’t afford to ignore your security. Not watching at all is akin to leaving the front gate unlocked and open. Your perimeter won’t do you a whole lot of good, if you don’t know they are trying to get into your home, until they are trying to knock down your front door.

Hence the need for surveillance and alarms. Properly executed, those will give you enough advance warning to allow you time to react. How much time will depend more on the distance from your perimeter to your door than anything else. So, while that time might not be any more than a few seconds, those few seconds are critical.

Since you will probably keep a weapon on you at all times and your main fighting weapon at your defensive position, those few seconds do two things for you. The first is to give you time to move from wherever you are to your fighting position. But the second one is even more critical; it’s to allow your mind the chance to switch from peace mode to fighting mode.

Surveillance Cameras

There was a time when I scoffed surveillance cameras, basing my distain on the fact that they would be unusable if the grid went down. Besides, in the event of an EMP, those cameras would probably be fried, along with everything else. However, I have to say that my opinion has changed.

That was before I discovered wireless cameras. Not only are those much easier to set up, but they are small enough to be discrete. Since they are battery operated, a power outage would not render them inoperable and chances are that they are small enough that they would not be affected by an EMP. So, while they aren’t the only thing I plan on depending on in the case of a breakdown of society, they are definitely part of my plan.

Cameras can be very useful for watching the main approaches to your home, especially if you can manage to keep them hidden. I live on a cul-de-sac, so I have one aimed down the street, which will show me anyone approaching my home. Another one is pointed at my front door, so that I can see anyone outside. If someone were to attempt to kick the door open or use a battering ram, I would be able to see it. A third camera watches the back of the house and allows me to see if anyone is coming over my back wall.

But here’s the problem with cameras. They require someone watching. My office is situated so that I can see people approaching the house, so I don’t need to see the cameras when I’m in my office. Rather, I put the monitor in the kitchen, as that is the main work area in the home. So, when we are working on other things, we have the capability of seeing what’s going on outdoors. The monitor is conveniently located where it can be seen while doing other things.

In the case of an attack, the last thing you want to do is be distracted by that monitor. That’s the job of a non-combatant, even if that means a child. Fighters have to keep their eyes and focus outwards, protecting the home. So you put someone there who is not fighting, and have them relay information to those who are defending the home.

Animals as Alarms

My favorite alarm system is my dogs. We actually train our dogs to be noisy, wanting them barking every time the mailman stops or someone walks down the street in front of our home. As such, it is all but impossible to come near my home, without them raising the alarm.

Dogs are naturally territorial, so barking at strangers is second nature to them. We reward them for it, rather than scolding them. We also take their barking seriously, with someone always stopping to look, every time they start barking at the front door. That shows them we are taking it seriously, as well as trains us to be attentive to their alarms.

While dogs are the most common animal used as alarms, they aren’t the only animals which can fulfill this job. Many animals respond when strangers draw near, raising the alarm. The key is finding one that will do so loud enough for you to hear.

  • Guinea hens (or guinea fowl) – These are some of the noisiest natural invasion alarms you can find. Guinea hens naturally raise a ruckus anytime someone comes around that they don’t know and will keep sounding off until they leave.
  • Donkeys – While not the noisiest animals around, donkeys don’t like strangers coming around and will raise an alarm.
  • Horses – Horses are very sensitive to anyone coming around their homes. However, they are not real loud. But if you are working with horses, such as for farming, pay attention to them. They will alert you to anyone coming around.
  • Geese and swans – Both of these birds are highly protective and mean. Trust me, you don’t want a goose chasing you. Not only will they make a lot of noise, they bite.

The Trip Wire

The most basic form of alarm is the trip wire. This can take a huge number of forms, depending on where you are putting them and what you have to work with. The idea isn’t that the wire trips the person, but rather that as they walk through the wire, their ankles or shins hit it, “tripping” an alarm.

Trip wires are normally mounted mere inches above the ground, making them hard to see. The end of the wire is either attached to some sort of mechanical alarm or to an electronic switch, which connects to the alarm. Our military forces have used anything from tin cans filled with pebbles to sophisticated pyrotechnics as alarms. They’ve also connected trip wires to claymore mines, making for a deadly ambush.

There are purely electronic variants of the trip wire as well, using laser beams instead of wire. But the principle is the same, the only real difference is that the laser trip wires require electricity to operate; something that you need to take into consideration, if you are going to use one.

Contrary to what you see in the movies, you can’t see these lasers unless you were to sprinkle some sort of powder, like flour or dust in their path. That would cause the light to reflect off of the floating particles, making the laser light visible. The only other way they can be seen is if someone happens to look directly at the laser light source.

For our purposes, probably the best way to use any trip wire is to attach it to a switch, which will set off an alarm inside our home. These should be strung across any opening or easily crossed area in our perimeter, letting us know whenever someone has come inside the perimeter. Combined with obstacles and booby traps inside the perimeter, the trip wire will provide us with enough time to man our defensive stations and be ready to repel an attack.

I’ve seen designs where people attached trip wires to mouse traps, which were holding light sticks. The idea with these is that tripping over the wire would cause the mouse trap to close, breaking the vial inside the light stick and making it glow. But, for this to work, someone has to be looking for the glowing light stick.

Other Alarms

There are actually a number of different sorts of area alarms available today, which could be useful in a defensive situation. While most of these were originally developed for use indoors, they are readily adaptable to outdoor use. At the most, you’d have to provide them with some sort of protection from the elements. Mounting them under the eaves of the house would do that.

However, the problem with all of them is that they require electricity. So a lot will depend on whether you have electricity available and how much of it you can dedicate to your defenses.

The other issue to keep in mind with these is that they will usually pick up everything. If a stray cat walks across your yard, you’ll find yourself running to your defensive position. While that is definitely preferable to not knowing that you have an attack in process, you could get tired of it quickly. Of course, eating the cat would solve that problem.

Booby Traps

As I already mentioned, the use of booby traps is illegal. Having said that, I fully intend to use them myself, when and if we are faced with a breakdown of society. However, I am going to be extremely careful to ensure that they are employed in such a way that I won’t have to worry about people stumbling over them by accident.

During the Vietnam War, the Vietcong were masters of booby traps. They killed or maimed a number of our soldiers that way. But they had a jungle to work with, making it much easier for them to hide their traps. Since we don’t have a jungle, we’re going to have to forego the swinging logs and pits filled with punji stakes. In other words, we’re going to have to forego the traps that can kill people. But we can still do things to injure and annoy them.

A lot depends on what sort of perimeter you have. If you have a large enough piece of property to dig a ditch around the perimeter, then you can fill the bottom of that ditch with punji stakes, thorny plants, sharp rocks and broken glass. All of these will injure and discourage, delaying any attack on your home.

If you have a fence, hedge or wall, it would be useful to sew a band of booby traps just inside them. That way, if anyone tries to come over the fence, they land in an area where they are likely to get injured. My backyard has three different types of fences, on the three different sides. One is a wood privacy fence, one is a cinder block wall and one is cinder block and wrought iron. Yet I plan on using the same tactic on all three sides, sewing a five foot wide swath of sharp objects inside the fenceline.

For sharp objects, I’m going to use a combination of broken glass, punji stakes and caltrops. My hope is that the visible punji stakes and broken glass will help to hide the caltrops, causing anyone who comes over my fence to step on a caltrop. I figure that if they do, they’ll provide their own alarm for me.

Another good place to put similar sorts of sharp objects is on either side of your front walkway, forcing them to stay there. In any confrontation with an unfriendly  group, you can count on them wanting to spread out, making their attack more effective. The sharp glass, punji stakes and caltrops will make that difficult and may render a few of them ineffective when the actual fighting starts.

In conjunction with these traps, you want some sort of obstacles across your front walkway. That way, they can’t just run up the walkway to your front door. Ideally there should be several barriers that they can move, which will slow them down. But the last barrier, which should be five to ten feet in front of your door, should be something that they can’t move, leaving them trapped in what is known as a “fire sack.” This makes an ideal ambush situation, with you able to ambush your attackers.

Making Caltrops

The caltrop is a simple medieval defensive weapon, originally intended for use in breaking up cavalry charges. They are made with four spikes, in such a way that one will always be pointing straight up, no matter how it falls. Hiding in the grass, the caltrops could cripple a horse that stepped on it.

The same idea will work for us and they are actually fairly easy to make. All you need is some nails, a welder and a grinder.

Booby Traps & Alarms - Caltrop

The caltrop in the photo above is made of two 20 penny framing nails. The heads were cut off and the ends ground to a point, leaving me with short steel rods that were pointed at both ends. These were bent in the vice, making a 130 degree angle. Each caltrop needs two nails, which are nested together, with the inner side of the angle facing in. then they are welded. That’s it.

As  you can see, these are easy to make, making it possible to make hundreds for a small time investment and very little cost. Scattered on the ground, they will be well hidden by the grass, awaiting a foot to find them. Once stepped on, they should penetrate the soles of most shoes, inflicting a painful injury.

While these can’t inflict life-threatening injuries, they can do enough damage to put someone out of the action for a few minutes and maybe even take the fight out of them. They’ll also do a good job making tires go flat, if they are left scattered on the road.

Dave Steen

About The Author: Dave is a 58 year old survivalist; father of three; with over 40 years of survival experience. He started young, learning survival the hard way, in the school of hard knocks. Now, after years of study, he's gray-haired and slightly overweight. That hasn't dimmed his interest in survival though. If anything, Dave has a greater commitment to survival than ever, so that he can protect his family. Click Here To Read More About Dave

Older Post Newer Post

Leave a comment - As always, please let me know your opinion in the comments section below. It's your opportunity to share some tricks with the community!

Please note, comments must be approved before they are published

Added to cart!