Fact: Flies move fast. Very fast. That's why you need something that moves even faster – like a fly swatter – to kill a fly.
But what if you don't have a flyswatter handy? Then, how can you catch and kill a fly?
I have tried whacking them with so many different items, from wooden sticks (bad idea!) to paper (way too flimsy) to magazines. All the methods are too slow, or failed for other reasons.
The trick of how to kill flies is the approach rather than the item used. Flies have nearly 360 degree vision, so sneaking won't help.
First, wait for them to land somewhere that you can strike against. Waving them towards an area can help, but isn't fully effective. Once it has landed on an acceptable area, approach the fly slowly, not making any sudden movements. Most of the time the fly will not move unless you get very close. Continue until you're within striking distance.
Once you're within striking distance, continue to move your arm that is going to strike the fly closer to the fly until the item you're striking it with is approximately 7-10 inches (18-25 centimeters) away from the fly. Maybe closer if you choose to flick the fly instead. You'll get the feel of it after a few failed attempts where it flies away most likely. Then comes the big moment: strike at it as fast as you can. Usually the fly does not have time to react fast enough to escape the blow, especially if the object you're striking with has some width.
I've killed hundreds of flies this way using my hand, rolled up paper, a shoe, or something similar.
First of all, make your job easier. Open the blinds/curtains at a window or turn on a single light to attract them to land on a smaller area. When closing in on them with your tool of choice, come in slightly behind them, since that's the direction in which they take off.
This is what I use:
Make fly strips. Take a sticky tape, usually duct tape and stick it together to form double sided tape. Now hang it around, you can attach pieces of food to attract even more flies, but you have to throw them out because they may rot if left to long.
Try using essential oils as a natural flyspray. These:
How to Make a Natural Household Fly Spray: These essential oils include Peppermint, Tea Tree oil, Orange oil, etc. Mixed with water they can kill flies if they get to close.
Body spray:
1 cup water
1 cup Avon Skin So Soft Bath Oil
2 cups vinegar
1 tbs. Eucalyptus oil (found in health food stores)
Optional: few tablespoons of citronella oil.
Room spray:
18 oz (2 1/4 cups) white vinegar
2 Tbsp dish washing soap
Use a hard book. A hard book can smack houseflies with accuracy as they don't move very much, but make sure you don't use to heavy of a book. Also, a wet rag can be used, as it has the appropriate weight. You could experiment and some people say use plastic platulas, but I've never really tried.
Both these methods may use sugary solutions which attract the flies, the funnels stop the from escaping.
Additional Info
From user Josho on how to make mini fly swatters:
MATERIALS NEEDED
1) a wooden chopstick (you can get these for free at a chinese restaurant)
2) a square of cardboard (about 4"X5")
3) heavy duty tape
4) push pin
STEPS:
1)take the cardboard and cut it to the appropriate size
2) make holes into the cardboard with a push pin (make sure there are a lot)
3.) tape the chopstick to the back of the cardboard square making sure that you start from he back and keep taping with one continuos strip.
The reason that flyswatters are more effective than a magazine is because of the holes. Moving a newspaper, magazine or other flat object through the air very quickly actually creates a buffer of air moving in front of the object you're swiping with, which blows the fly out of the way.
As well as avoiding the above, a flyswatter's holes enable it to move faster, thus increasing the chance of whacking the fly.
So, if you want to improvise a flyswat, I would recommend using any device that has holes in big enough for air to pass through but not big enough for a fly to pass through.
I would also recommend getting your arm as close as possible (moving slowly) before swatting. This gives the fly less time to react to your movement and decreases the chances of escape.
Finally, for a less active approach, you can try killing flies without swatting them. A jam jar half-full of sugar water with some holes cut in the lid always worked quite nicely for me, or there are numerous commercial products that attract and trap flies - for example, on sticky paper.
A way I usually use is: catch the fly, then throw it out the window (or a door. Or into a spider's web. Or smash it against the floor, if you feel particularly angry).
To catch the fly, I use method 2 (of part two) described here.
That is:
There is a good chance the fly will feel your approaching hand and decide to fly away; however, it will take off vertically at first, so it will actually fly into your grasp. This method is quick enough so your reaction time is not a factor: you don't have to react to anything. So only your muscles limit your speed, and they seem to accelerate faster than flies can do.
The distances I specified vary widely; they depend on the type of the fly, its mood and (maybe most of all) ambient temperature. When it's cold, you might want to make your swing deliberately slow, so the fly has time to try to escape.
I'm rather surprised I haven't seen it yet, so give it a chance before you write it off: rubber bands. Preferably the wider ones (1/4" or so).
Just like you are back in elementary school snapping your friends, pull it back over your finger and let it fly. In 100% honesty, I find it easier to rid flies with this than with an actual flyswatter, I'm assuming you might find the same.
Aiming is very easy, as you can usually get within a foot without spooking them, and because of the natural bendyness of the band, you only have to get relatively close to your mark to actually cripple or kill the fly.
Pros:
Cons:
One thing that I find works with just about any insect is a soap spray. How stuff works recommends 1 to 2 tablespoons liquid soap per quart of water, but I kind of just wing it. I usually get a trigger-sprayer (like the kind Windex and other cleaners use only I buy them empty), dump some water and soap into it and shoot whatever insect needs taking out.
The main drawback is that it's a liquid so you only want to use it where that won't be a problem (also, it will sometimes ground the flies but not immediately kill them so you might need to squish them after the fact with a paper towel or something if you didn't use enough soap).
An advantage of the sprayer is you can fiddle with the stream -- use a wider spray to ground the fly without needing to be too accurate then move to a narrower stream once it's stuck on the floor to increase the amount of soap you're sending to it. Additionally, you are spraying soap so you can clean and kill at the same time.
I have found that this approach (soap sprays) works on just about any insect - flies, cockroaches, centipedes, cabbage worms, etc. so it is a good tool to have in your arsenal in general.
Get a drinking glass, some dish washing soap, and some warm water. Add a little soap to the glass and fill to below the top with warm water.
Sneak up below fly sitting on your ceiling and slowly raise the glass to capture the fly. Optionally use a the below piece of equipment if you are vertically challenged.
???
Profit.
(This was about 1 minute of walking around my house fly catching. That's about 0.15 FPS (flys per second))
I have an eco-friendly way to get rid of flies, without the need to actually kill them (you can if you want).
*If you curl your hands to create a little bowl, you won't kill the fly and just trap it, which also leaves no mess on your hands and you can let the fly live another day. Or you could just throw it into a spiders web and watch it get eaten alive ... Whatever floats your boat!
My weapon of choice is a dish towel. Simple, always available (you can use any sufficiently light towel).
Grab one corner with your right hand, don't twist it but let it hang. Pass it above and behind your right shoulder and grab the other end with your left hand. When you want to strike, pull firmly on both ends and release your left hand, releasing a fast whipping motion. Whack !
Stronger flies won't die from the hit alone, but you have a few seconds to step on them while they're dazed.
Electric Tennis raquet - http://www.amazon.com/Battery-Operated-Tennis-Racket-Shaped/dp/B003U55W6Y
Never miss a fly again. It uses electricity to kill flying bugs.
There is always the use of chopsticks to catch the fly. @darthnesscoveredthesky mentions chopsticks in his set up, and these are great as tools themselves as well.
The problem, as pointed out by @starsplusplus, is air resistance. Chopsticks could be used as a useful tool with minimal air resistance.
Flies have tiny little hairs which are sensitive to the slightest change in air pressure. When you swat at them with your hand, the change air pressure will alert them and they will fly in the opposite direction.
The only way to effectively kill them with your hands is to confuse them by coming from two sides at once. Slowly position your hands on both sides of them just above where they are resting. Slightly cup your hands and make a clapping motion right above them. They will fly right into your hands and you will either catch them or kill them.
I'm surprised the following was not yet proposed. You actually don't need any items. Only your hands.
But to understand why that technique works we need to know something about flies. As mentioned by others before, flies have almost 360 degree vision, so they will see you coming. but they have one big handicap: They can only concentrate on two things.
Knowing this, you can slowly approach the fly from behind with your preferred hand and index- and ring-finger spread apart. With any finger of your other hand you pull back your middle finger. It should look something like this:
Your index- and ring-finger touching the surface, you move towards the fly. It will concentrate on those two fingers and won't notice your middle finger. Move your hand really slowly, so you don't scare the fly. When the fly is right below your middle finger it's time for the kill. Just pull away the finger pulling back your middle finger - it will snap down and squash the fly.
You will get a dirty finger, though. But when approaching slowly enough this technique works every time.
This approach however has one downside. It only works good on flat surfaces big enough to fit your fingers next to the fly.
I use this every time a fly lands right on my desk or somewhere near me. I actually prefer using my hands rather than striking with a magazine, since the shockwave of the moving magazine can simply blow away the fly.
I just roll up a piece of cloth (shirt, towel, scarf) and start swinging it around. It is basically like a flyswatter but much more effective
My favorite way to kill a fly is with a salt fly gun. (Google those words and you will see what it looks like.) It looks like a toy shotgun or rifle. You cock it and when you pull the trigger it blasts a small amount of salt at the fly. However, if you don't have a fly swatter you might not have a fly gun either.
Regardless of how you kill the fly, one thing that may help is to immediately close the door of whatever room you are in. Cutting down on where the fly can go will allow you to kill is more easily. It is also helpful, if you can shoo in into another room, to pick a room that contains lighter colors. It is very difficult to see a fly against a dark background. With the door(s) closed and a clear view of the fly you may then be able to search around for something to hit it with, whether it is a shoe, a rolled up newspaper, or whatever. If you are feeling adventurous, try killing it with your hands, either by clapping your hands as it flies between them, or batting it out of the air to stun it, and then finish it off before it recovers.
If the fly is on something you don't want to damage (for instance, as vase or trinket), try picking up the object from behind and then moving it towards your hand. I actually killed a fly like this recently. The fly won't sense the movement of your hand as easily as your hand is not moving.
It's a tried method:
Take a paper and apply oil to both the sides of the paper
To one corner tie a thread, now tie paper near a tube light or any bulb.
Flies are attracted to bright light.
Switch off all the lights except one.
You will notice the flies stuck to the paper.
Yet another method; for completeness since I didn't see it in the other answers.
Blow air gently on the fly. Then it's easier to swat it by hand.
Just use your lungs and mouth to make a gentle wind strong enough to make the fly grab hard to the surface to avoid getting swept away by the wind. The same gripping mechansim they use to sit upside down works for holding tight to a surface in a windy day. But the back side (for the fly) is a delayed take-off since it has to loose the grip to get away.
If you have a little time and are in a reasonably small space, there is a technique that will make it much easier to catch (or kill) the fly.
First a bit of background. A chemical called Adenosine triphosphate (ATP) is required for muscle contraction. When a muscle fiber contracts, it consumes a tiny amount of ATP from its reservoir. It takes a bit of time to refill the reservoir, so a lot of continuous muscle activity will deplete the reservoir and make muscle contraction quite difficult. This occurs in your own muscles and, more importantly, in a fly's wing muscles.
The idea then is to simply keep the fly flying until such time as it has used up so much ATP that it simply cannot react to even the slowest attempt to swat it.
What I try to do is corral the fly into a small room in the house (bathrooms work best), often using the "single light on" trick mentioned in @Mooseman's answer. Then, whenever the fly lands, I wave my rolled up newspaper (or whatever) at it in order to alarm it and keep it flying. Over time, the fly reacts more and more slowly to this harassment. After a few minutes I can just tap the fly with my weapon of choice with no trouble whatsoever.
I catch them by hand. You just wait for them to land and then slowly bring your hand up behind them (or in front. Doesn't matter provided you are very slow). Have your hand ready to close/catch, then move like lightening! No need to kill them, just relocate them back outdoors (and wash your hands)!
My girlfriend left our sliding glass door open last week and we got so many flies in our bedroom it was crazy. I just took a bowl, put warm water and a table spoon of molasses and a squirt of dish soap in it. The next morning I had caught almost every fly. No work at all on my part. One note, you can use honey instead of molasses, but with the molasses the liquid is black, and you can't see all of the dead flies until you pour them out.
For those of you that are curious, the sugar attracts the flies to the water, and from what I understand the dish soap makes it so the flies can't land on the surface of the water, then fly away. They "fall in" and drown. (poor little guys).
We used to get tons of flies while in Iraq. If you wait for one to land and a vertical surface, then take a lighter which is turned up on high. Then light the lighter and it will fry the fly instantly. I'm thinking of patenting the idea, a small lighter with a big flame, and call it Fly Fry, just need a few investors.
This sounds really weird, but it works. I accidentally left the lid off a pickle jar after giving my kids the last two pickles. When I saw the jar about an hour later, there were 3 flies dead in the vinegar.
A rubber band. I was a paper boy and always had paper rubber bands. Break the loop. Strike from about 8 inches away when they land. At school I would wait for them to land on my desk and get them every time.
Use a hoover without the filter bag.
Turn on the hoover and point to the fly. The vacuum will pull it in, and the fly will die when passing through the internal fan.
Too cruel (and noisy) though. >=/
My favorite tools are a propane torch or glass cleaner, depending on the environment.
For years, I used a Salt Gun, but my wife complained about the salt, and then one day the kids left it out in the rain and it stopped working. Since then, I have used these two tools. Each of them is far more effective than a swatter, even more effective than the salt gun.
With the torch, I give a quick press of the electric ignition to let out a quick burst of flame. You want to aim for just beyond the visible flame, and you will do fine. Depending on your aim, you will vaporize their wings, and perhaps even their appendages, and they will drop to the ground. Most of the time, I find tha they are instantly killed. You do need to be careful of your backstop or what ever the fly is perched on. You won't want to hit them if they are sitting on something fragile or flammable, but ceilings, walls, tables, counters, etc are all fine, as long as you are careful about the intensity and duration of the flame. Just give the button a quick flick, nothing more. I prefer this solution to the salt gun, and have scored may double and even quite a few triple kills with this, as you can angle the flame to wash over one or more flies if they are close enough. It also is possible to take them down on the wing, just be careful of where you aim it. It also does not disturb the nearby flies, so you can just move about a room taking them all down with a quick depression of a button.
The glass cleaner is useful for cases where the backstop would make the torch unsuitable, such as flies landing on a TV or monitor. Just give them a spritz, and they will be unable to fly and fall to the ground. While they may not be killed by this technique, I don't think that is necessary, as I police the body with the same paper towel that I use to wipe the cleaner off of the screen. If you need to have a lethal spray solution, and you want to leave dead flies laying around your house, you can pour some alcohol in a spray bottle. The spray bottle is also a tool that will allow you to reliably take down flies in the air.
What kind of sandals do you have? Birkenstocks work great. Hold it by the toe strap and swing it. Put your wrist into it. Try to swing it at where the fly will go instead of where the fly currently is. The impact flings it across the room and stuns it or kills it.
If you are fast or have some martial arts training, you may find you can catch flies with a punching/grabbing motion. I used to be able to catch fruit flies, but I never tried larger flies.
Wait a fly to land, then slap hands over it. When your hands start moving, the fly takes off vertically and gets right between your palms.
Do you have a fan? It would be a wonderful tool to kill them. As you know, fans blows with their front side, but the rear side will suck and (hopefully) cut the fly in pieces. Fly is quite a small thing, so I doubt that it will make and damage to your fan.
Also, any kind of sticks with motorized propellers, they'll also work.
This would be an example of such stick, but its quite simple to make one with lego :)
And mini-vacuum cleaners would work too (e.g. for automobiles). Of course, normal-sized vacuums would work too, but I don't think its easy to chase a fly with big ones.
Another way (maybe not as efficient) - try to fill some of your spray bottles with water. Then spray some water on a fly (do not recommend to do it near some technic :D ).
I used these non-salt guns in my younger days. http://www.amazon.com/Martin-Paul-100-75-Flyshooter-Original/dp/B0001UZUW2
and recently ordered more for the car.
The salt guns are nice, but they leave salt everywhere, I assume.
