In a world where people find aliens invading their homes, with what household object or objects found on the street or nearby, could people defend themselves against the invader?

The rules of the invasion are as follows: in every household on the planet at the same point in time one such alien is materialised. If the alien invader in your house is killed, then your house is safe from further invasions.

I need a possible scenario/scenarios on how and with what strategy or device ordinary people defeat their alien opponents so that, lets say, 10% of people in the world is left standing (the % is not as important, just needs to be under 50%).

Note that the aliens are extremely evolved in a way that it is very smart but also very, very tough to kill. It has skin that bounces off melee weapons, it is bulletproof against small and medium caliber bullets, blast-proof, resistant to fire, can last extremely long without oxygen etc. Also note that people are totally surprised by the attack in their home.

Should you need to do so, you can furtherly drop the resistance of the aliens at your will to suit your "killing situation", but to a degree that the alien will still be considered "pretty goddamn tough". Alien species is a humanoid and is also the size of an average adult male. Typically only one member of the species would invade the designated household.

  • 8
    $\begingroup$ How large is it? Does it fit into a microwave oven? What about poisoning it? Maybe lay a trap with it's favorite food (I could imagine a story where a character has to cut off a limb and stuff it with poison because the creature only eats humans). I should tell you that this question is about idea generation and cannot be fully answered - which I believe why this will be closed pretty soon. If you are looking for idea generation, this is the wrong forum, especially since you have not defined your alien well enough $\endgroup$
    – Raditz_35
    Oct 17, 2017 at 12:41
  • 1
    $\begingroup$ Do they come here to pick a fight? Else try to exchange information, knowledge, essential stuff with them. "If you know your enemy and know yourself, you need not fear the result of hundred battles."-Sun Tze $\endgroup$
    – user6760
    Oct 17, 2017 at 13:07
  • 3
    $\begingroup$ @user6760 "Hail to you interstellar traveler! Do you come in p..." WHACK "Ow, that was not nice! Now will you pl..." SMACK "Look.... maybe we got off on the wrong f.... yikes!!" PEW PEW PEW. youtube.com/watch?v=rMdC45S79uQ $\endgroup$
    – MichaelK
    Oct 17, 2017 at 13:13
  • 1
    $\begingroup$ Give the creatures an Achilles Heal - a particular weak spot on their body. Maybe the reproductive organs. Usually, these are vulnerable areas. Excretory areas, that offer a vulnerability. Even cockroaches can be killed. Maybe a particular sequence of actions - one to expose the vulnerability, the second to complete the kill. The first could trigger a reflex action. A bright flash of light (camera flash), startle reflex, expose a vital organ, go for the kill. $\endgroup$ Oct 17, 2017 at 14:36
  • 2
    $\begingroup$ Country Music seems to be a good choice. There's even a documentary about it: en.wikipedia.org/wiki/Mars_Attacks! $\endgroup$ Oct 20, 2017 at 11:46

13 Answers 13


I'm going to learn from ACAC and DannyBoy and add a little more on.

Clearly, if you can tie the creature up with ropes or extension cords (hell, I have enough bubble wrap and duct tape in my house to make a serious go of it), then you have plenty of time to experiment. But first you need to buy that time.

See, when the alien shows up you'll be surprised and not have time to set up elaborate Home Alone-style traps, so you need a way to put the alien on the floor fast so that you can tie him up and go get your power sander. The key here is...

wait for it...


That's why people used those gigantic warhammers and maces during the middle ages. Because the shock from a heavy impact travels through steel plate-mail. Much less some alien chitin. So seriously, I'm suggesting that you pick up a crowbar, rolling-pin, or other heavy object and whale away on the alien's head til you drop him stunned.

Then he's yours.

Edit: The aftermath -- "Christ, Tom, you shoulda seen it. Guy just materialized out of nowhere into the kitchen. Judy clocked 'im with a cast iron skillet, and then I picked up that stupid schmancy marble cutting board and let 'im have it. First time a wedding gift was actually useful. Anyway, guy dropped like a stone, 'n we tied him up with extension cords. Turns out Bar Keeper's Friend eats right through that exoskeleton..." "Yeah, similar story here. Alien popped into the garage where Billy and his band were practicing. They beat him down with electric guitars. Billy said it was 'epic'."


General note: all of this requires dialing back a bit of the resistances you specified.

Rifle or shotgun

Even in Sweden — that has very strict gun laws(*) — there exists 2 million legal privately owned weapons on a population of 10 million. Half of those are hunting rifles, a quarter are shotguns.

If the setting is the US, home-owned guns would be even more prevalent.

There is no such thing as "bullet proof", unless you have Really thick and hard hide. A hunting rifle will punch through even heavy personal armor. A shotgun round to the head should at least blind the alien.

Cooking knife, meat cleaver

Self explanatory. Even if they are not made for combat they are a tremendous force multiplier in the hands of someone trained.

Home-made flamethrower

Pressurized household containers are usually driven by propane. Run that through an open flame and you got yourself a little flame-thrower. Even if it will not be killed by the flame, the flame-thrower can still be very unpleasant, damaging or otherwise detrimental to the being.

Baseball bat

...will serve as a decent melee club.


Works on zombies, why not aliens?

The house itself

If push comes to shove, sever the gas line, sneak outside, wrap a rag/t-shirt around a rock/baseball to get some weight to increase throwing distance, douse the cloth with fuel from the lawn mower tank/petrol can, light it on fire, and chuck it in through a window. If it is a brick house you can expect the walls to give out and the roof to fall down on the nasty.

enter image description here

House destroyed in gas explosion. The occupants made it out in time.

Malmö, Sweden, 2007. (Image source)

(*) You need a license for every weapon you own, and you need a valid reason for having each of the guns. Valid reasons include hunting (you need to be a licensed hunter too), sports shooting, but not self-defense.


Assuming you have enough time (and presence of mind), most houses in North America are equipped with at least one 240V outlet with anywhere from 40 to 100amps for the clothes dryer or electric oven.

Cut the cable from the appliance end, separate the positive and negative ends of the wire and strip away some insulation, sharpen the ends of the wire if you want to, then turn the circuit breaker back on and lure the alien into grappling range. Stick the bare wires into it and enjoy the show.

  • $\begingroup$ Though this does somewhat assume you know about and have circumvented any precautions your house/appliances may have. For me to use this method I’d have to jam open two different breakers, or all I’d do is give it a nasty shock. $\endgroup$
    – Joe Bloggs
    Oct 17, 2017 at 18:27
  • 1
    $\begingroup$ I think if I try to attempt something like this... a) I will be killed while trying to move my oven, b) I will be killed while trying to figure out which specific cable I need, c) I will be killed while trying to repurpose my finally found cable into a weapon, d) I will be killed while trying to 'plug' my alien into an outlet; e) I will be killed while cursing that electrician who did the wiring in my house because he took care that I do not electrocute myself by accident ... I am not a survival type $\endgroup$
    – Olga
    Oct 18, 2017 at 4:28
  • $\begingroup$ @JoeBloggs simply do the procedure with an extension cord that is only plugged into the socket after it was prepared. $\endgroup$
    – Burki
    Oct 18, 2017 at 10:19
  • 2
    $\begingroup$ @Burki: the breakers in my house trip if they detect a connection to earth. I guess I could lure the creature into a rubber mat, but then there’s also fuses in all the plugs and a second set of breakers for if any individual appliance (can we call improvised monster killing tools appliances?) draws too much power. It’s spectacularly difficult to apply anything but a momentary jolt. $\endgroup$
    – Joe Bloggs
    Oct 18, 2017 at 10:54

Well, it can't be immune to every poison, and it probably isn't protected against both extremes of the pH scale. Among all these people desperately looking for makeshift weapons, someone will probably come across something to fling at it that's effective (potentially not something that humans would have a problem with).

You could count on the substance being common enough that 10% of the population are able to use it to their advantange (or the alien accidentally kills itself with the substance while distracted by pursuit, e.g. breaks a wall and dies on inhalation of a chemical in the dust).

Since you haven't said communications were cut, you could also count on people buying themselves just enough time to Google "how kill alien invader" and see what worked for everyone else. That way, however unlikely the solution, it only has to be discovered once for that information to spread.

And that's not even getting into microbes (or insects!) We've got all kinds of organisms that evolved just to get into teeny cracks and destroy everything. Lichens destroy rocks. It might take time longer than any human has, granted, but it would be pretty funny to see something taken down by a lichen.

You could also just find a way to cut the alien off from resources, trapping it long enough to starve to death.

In short, if being big and well armored were all it took, rhinoceroses and similar megafauna wouldn't be endangered. If being big, well armored, and intelligent were all it took, Genghis Khan would have taken over the entire world.



The alien does not have super-man strength but is simply resilient to fatality.


There was no mention of its bones being unbreakable or the muscles too tough to pull. Breaking of bones and pulling of muscles should be extremely painful, however not necessarily fatal. This way, your trained person could snap the aliens bones or neck, rendering it incapacitated although still alive.

Another way would be to trap it and just keep it indefinitely, meaning its resilience is not really a problem since it can be worked around. Simple pit-fall traps, bear-traps and similar can be widely used. They will be stuck and then a more well-equipped person or organization can swing by and finish the job.

You could introduce weak spots in its armor, say in its joints or similar places. It would still be hard to kill since the areas are quite small.

  • $\begingroup$ Variation: Incapacitate without oxygen (like underwater) for long enough until it does finally expire. Then you can re-use the trap. $\endgroup$
    – user535733
    Oct 17, 2017 at 15:26
  • 2
    $\begingroup$ Finally! A use for my collection of antique bear traps! $\endgroup$
    – Joe Bloggs
    Oct 17, 2017 at 18:27

Rope is the easiest thing to use. Trip the alien, tie the alien up and then it can't do anything. Then you can slowly break the tough skin and peel it off and torture the alien slowly to death. Everyone who surviving in the neighborhood can come out and do some the torture, it will be a fun experience for the whole family. Each time one is captured and killed the whole neighborhood can have a party. I'm sure everyone will enjoy killing the alien party, especially the ones who lost loved ones to the alien before everyone figured out how to fight them.

  • $\begingroup$ Is it feasible for someone under 50kg (120 lbs) living alone and being greatly shocked by a hostile alien guest? $\endgroup$
    – Olga
    Oct 18, 2017 at 4:30

Maybe it has a critical metallic internal organ that is about 3 cm is length and is thus a perfect microwave receiver? That carapace resists all externally applied heat, but unfortunately its race never made convenience foods. After a great gun battle, one of them is pressed up against your drunk uncle's wasted old microwave that is leaky as hell and should have been discarded years ago while he heats his microwave pie.

Also, is it immune to chlorine? And hydrogen sulphide? Both of those are easy enough to make.

For fun, you could have the activator from a fibreglass resin (or two part epoxy) create radical chain reactions that completely solidify its blood.

Or go Reverse war of the worlds: These guys need their internal bacteria to live. If they eat penicillin, they go bye bye.

Or they get addicted to opiates really easily. Too bad they showed up at a dealers place in Minneapolis.


An attack that might be sufficiently uncommonly attempted, yet might be fatal to this species, would be attacks with common household chemicals. Perhaps these aliens which are built to take a pounding from any number of kinetic attacks are simply susceptible to being poisoned by different substances than humans. They're aliens... it just makes sense that they have a different body chemistry.

Additionally, the way that this question is written, it seems that these aliens are teleported in, and that they are sufficiently tough and confident that they aren't wearing an environment suit... perhaps they are invading us because we have a similar environment to their homeworld's, or perhaps they are genetically engineered to cope with our environment and the human propensity to use kinetic force upon our enemies... whichever explanation is correct is irrelevant.

I could imagine these aliens to be a sort of intelligent, amorphous blob, capable of extruding limbs in order to perform various physical tasks. Being amorphous, kinetic attacks would have an effect little different to that which they could do for themselves, namely to push parts of their bodies around. They would have no differentiated organs that might be injured, and they might be highly tolerant to a change in their body temperature, such that freezing or burning would have little effect.

Household detergents and soaps are harmless enough to humans, but with their different biochemistry, they may be quite toxic to these aliens, with their amorphous body structure.

For all the human households that the aliens invade and encounter the occupants, some will run. They can be discounted, as the aliens could easily take a form that could run the fleeing humans down.

In other households, the occupants may throw punches, heavy objects, sharp pieces of metal or pyrotechnically-propelled pieces of metal... you know, your basic kinetic/penetrating attacks, to which these aliens are apparently adapted to survive. If the aliens respond in kind, humans are much weaker and far more susceptible, and would typically succumb easily.

However, in a minority of households whose occupants are in attendance at the moment of the invasion, some will be cleaning, either their dirty clothes, their dirty dishes, floors, pets or even their own bodies, and when suddenly confronted by a belligerent alien, they throw that which is most readily available to them: the soap or detergent.

They may be surprised that these chemicals which are relatively harmless to humans - causing at worst temporary blindness or an unpleasant taste in the mouth - are quite toxic to these aliens, who react much as we might if subjected to some highly toxic substance such as VX, by rapidly succumbing to convulsions and death... or they may simply "dissolve" into a puddle of goo.

From there, those who have encountered the aliens, have poisoned them and survived would be able to pass on the knowledge of their discovery to those who are away from their homes.

Once it is known that the aliens are susceptible to soaps and detergents, it isn't much of a stretch for people to fill water balloons and water guns with detergents and go hunting. Even common bubble wands may be able to deliver a sufficient amount of detergents to the aliens if used upwind. Fire fighters could arm themselves with their foam fire-fighting equipment that would become the true heavy alien-killing artillery.

While many people may be killed trying to defeat the aliens invading their homes using kinetic force and being bludgeoned to death by the physically far superior aliens, once word gets out that their weakness is soap, the balance will shift just as dramatically in the humans' favour, and from our perspective, the fight would be almost comical, save for the humans killed before and during the process of routing the aliens.

This scenario could easily result in the sub-50% human survival rate that the OP desires.

Soaps could easily be substituted with other common household chemicals if the OP so desires.


The bed

When aliens invade, a homeowner plays bogeymen and hides under the bed. With a shotgun, which makes him scary. The gun can't hurt the aliens, but the mattress is stuffed with horse feathers, and aliens are deathly allergic to horses. (M. Night Shaymalan can send me a check)


The homeowner uses a bottle of whiskey to give the new arrival a proper name. The alien, not accustomed to the taste, has a gagging fit. The homeowner shepherds the choking alien into the trunk of his car, and leaves it in neutral on a hillside.

Combat Roomba

An alien can't be sure the Roomba isn't the homeowner, so it needs to neutralize the threat. It is no trouble for it to destroy the device, but in the process it is seen by the upward-facing camera. Now the NSA knows it's in the house, and can consult the device's internal floor map to know precisely where to aim a missile or laser. If the homeowner is hiding in the bathtub there is a chance he might survive.


I do not think that for ordinary people killing is a feasible strategy. Your average Joe has neither means nor training to kill anyone. And if they attempt to do so they will be more likely to endanger themselves or others than to inflict any significant damage on an alien.

Even in the USA with its lax gun laws, only 35-40% of its adult population owns guns. (The majority of guns are in the rural areas.) It still seems to be a huge number of armed people. However, only half of these people have their guns loaded and within easy reach (what the latter means is not fully clarified, though) when they are at home (but not when they are elsewhere). But most importantly, only about 14% of gun owners use them regularly either for hunting or in the range. There is no easily available statistic on how many of these people are trained to kill an enemy in a battle situation. Not to mention that the majority of personal firearms are handguns.

So, in other words, even in a country as the USA with lots and lots of guns, there will be only a handful of people remotely prepared for dealing with the invaders.

Considering all of this, average Joe and Jane (their Joe, Jr and Jane, Jr) would be much better off dropping everything and running away... hmm, strategically retreating and regrouping with some local thugs independent justice enforcers (in urban setting) or some cowboys/hunters, preferably (ex-)military (rural setting). If these options are not available banding together with neighbours might help.

Once they have numbers on your side, Joes and Janes can proceed with digging traps, using household items for inducing blunt force traumas, etc. The important thing is to follow the KISS doctrine (keep it simple, stupid).

And here is a memo for an average Joe/Jane:

DO use:

  • long guns, if you know exactly what you are doing and you (and your friendly neighbours Mr and Mrs Smith) are at a safe distance;
  • baseball bats, crowbars, cast iron skillets, and other blunt objects (don't forget that you have to be able to lift and swing them!);
  • shovels (for digging only, do not try to fight with them unless you have some training);
  • cars (do not forget to use your seatbelt!);
  • trucks and heavy trucks (still use a seatbelt);
  • machinery (tractors, bulldozers, auto-loaders, saws, etc.) that you know how to operate (there is no time to read the instruction manual!);
  • ropes, cables, duct tape, etc. (do not play a cowboy, use them as ties and ties only!)

DO NOT use:

  • sharp objects such as knives, machete, swords, spears, and so on (way too dangerous for yourself and your friendly neighbours unless you are a samurai or a knight, but in this case, you are no longer an average Joe/Jane);
  • home-made flame-throwers and/or fireworks (remember Mum told you not to play with fire? Listen to her! IT IS dangerous);
  • anything you do not know for sure how to use....

Remember: DO NOT BE A HERO! Be a part of a non-heroic group. They survive longer.



You have given almost Superman-level defenses to your aliens. You say:

It has skin that bounces off melee weapons, it is bulletproof against small and medium caliber bullets, blast-proof, resistant to fire, can last extremely long without oxygen etc.

So based on that, the average home resident is going to die. In the US, some significant percentage of people will have access to firearms. But those will be small or maybe medium caliber rounds. Humans might have melee weapons, but most of those are going to be useless, as you state.

The people who try those weapons die first, as your aliens neutralize the threats before they neutralize the less threatening occupants.

Some percentage of humanity might try more drastic attacks. Chemical weapons (mace, pepper spray, bleach, etc.). Some might be cooking meals and try boiling water or something. But generally, those will be too small a group to matter, even if they succeed by some chance.

They won't (or shouldn't) have time to devise or carry out any significant military-grade counter-attacks. Not during a surprise attack in their homes. At least, not in any statistically relevant number of households.


You state

in every household on the planet at the same point in time one such alien is materialised.

So when your attack begins, some percentage of humanity will be at work, school, or otherwise away from their household. What percentage depends on when the attack occurs (on a major religious holiday or a during a typical work day? During morning or evening in what time for your story's primary continent? Was the time optimized for destruction, or chosen randomly?).

Remember that if it goes down at 9pm at location X, that's not 9pm for most of the planet... But even if the attack occurs at 4am local time, remember that some people in that locality will be away from the house. Whether that's because they are working the night shift, or whatever...

Likewise, some percentage of humanity will be on ships, planes, or in cars. Some will be homeless. Or in hospitals/hotels. You get the idea.

Your ten percent survivors is most likely drawn almost entirely from those who were already away from home when the attack occurs. They get word of the attack, and do the smart thing -- they don't go home.

Your job

Your job, then, is to decide precisely when the attack occurs, how long it lasts, and what the aliens do next -- do they beam back up to their spaceships and leave? Or do they then move on to business addresses?

Decide those factors, then you can start to estimate how many people might have been out of the house for each timezone/city/area at that time / date.

Hail Mary

I hesitate to throw this in, but you could take the War of the Worlds1 tactic. Some households have a common(-ish) household item that your aliens are susceptible to. Perhaps it is a flowering plant, dog fur, wheat, rice, etc. or a cleaning agent. Or black lights (yay dorm room decorations2). Or tobacco smoke.

Whatever the MacGuffin is, make your aliens completely weakened by that thing.

I don't personally like that tactic, but it works. Especially if the thing is something that seems relatively harmless to humanity, but some super-advanced aliens might not have considered in their defenses.


he quickly discovers that all the Martians have been killed by an onslaught of earthly pathogens, to which they had no immunity: "slain, after all man's devices had failed, by the humblest things that God, in his wisdom, has put upon this earth" wikipedia

2 For the purposes of this invasion, do dorm rooms count as households? Hotels? Campgrounds? Army bases? Here's another potential "away from home" pool, if they don't count. How you define the alien's attack vector matters.

  • $\begingroup$ Not even remotely Superman levels. Maybe Spider-man or weaker version of the Iron Man armor. $\endgroup$ Jan 26, 2019 at 20:55

Killing stress

Humans are unusually strong against stress. Compared to other animals, we're practically indestructible. Most creatures are unable to cope with multiple large spikes of stress. Most creatures are downright unable to cope with long term stress. They simply die from it. Humans on the other hand can endure sometimes even years of high stress, before they get sick. But death by stress is very difficult.

The aliens could get stressed from attacking humans. They might be more suitable for short bouts of stress when attacking. But the humans can scatter, making them stress longer to get all of them. They can scream and shout, which can be irritating. But it might be more mundane. The TV screen with large amounts of flashing images can distract and overstimulate, if not give an epileptic shock. A shower could overstimulate with hot water or water vapour over it's skin. Or possibly they might see certain wavelengths that make them go wild, like a goldfish seeing lasers from a remote control or maybe they even see wifi waves sloshing about.

The stress can incapacitate both on short as well as long term. Simply by running away screaming we can defeat the aliens.


Maybe the aliens are emotionally fragile? As in, they're more or less indestructible but if they get told GKY enough, they'll do it?

Note, this would open up a broad range of strategies for dealing with them, depending on the details of their emotional fragility. Maybe they need to be shamed, maybe guilted, maybe reasoned with morally, maybe just abused or cussed out. Maybe the communication that induces them to commit suicide needs to be translated into their language. Or falsely framed as a communication from their own kind.

The every day objects used are therefore ones own mouth, audio equipment, letters, radios, computers, or any particular instance of communications technology.


You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .