Introduction: Plastic Bottle Mosquito Trap

Picture of Plastic Bottle Mosquito Trap


Hello dear friends!

As some of my followers already know, I live in Bologna (Italy), in the heart of Po river Valley.

This area is known as the wettest one of Italy. This is due to terrain, level (a lot of areas are UNDER sea level) and weather.

These factors result in very hot temperatures in summer, very cold ones in winter, an incredibly thick fog but, mostly, giant and aggressive mosquitoes.

There is a city, Comacchio (only 55 miles from Bologna), that is known as the "Mosquitoes Town". XD

Obviously is nothing tropical, but it's very annoying!

It's really difficult to enjoy summer evenings without using pesticides, sprays or other stinky poisons. Or, you can always avoid using anything and... be eaten alive by these little vampires.

While mosquitoes are useful for the ecosystem (did you know that mosquitoes are the main cocoa plants pollinators? No mosquitoes means no chocolate!!!), we don't want them to fly around our garden and bite everything that's alive, pets included.

In this Instructable, I want to show you an all natural and potentially free way to create an efficent mosquito trap with little more than a plastic bottle!

Why potentially free? Because we will use materials that are always present in our home!


Let's start with our shopping list.

Step 1: Shopping List

Picture of Shopping List

For our trap we will need:

  • Plastic bottle (2 liters one is good)
  • 4 spoons of white sugar
  • 10gr (0.70oz) Brewer's yeast (freeze-dried one or fresh)
  • 200ml (6.75oz) water (and a pot for boiling)
  • Tape
  • Black cardboard (or similar dark covering)
  • Scissors

Optional for hanging

  • String
  • Liquor can container (like Baileys one, look at the images for more info)
  • Drill

If you have the liquor can container, you won't need black cardboard, we will see why.

NOTE: A lot of users reported me different results. Someone have found a full trap and some other an empty bottle after several attempts. You should experiment a bit by changing the amount of yeast in each traps, in fact only some kind of mosquitoes are attracted by this trap and the amount of CO2 released change the effectiveness depending on climate/humidity of your zone. For example, I've found a full bottle on the first attempt and much less dead mosquitoes in the next two bottles (with same recipe). I'm experimenting different mixtures in these days ;)

As you can see, these are very common and easy to find materials.

I didn't have to buy anything except for the brewer's yeast (I can't find fresh one...darn).

Let's move on the first thing: cutting the bottle!

Step 2: Prepare Your Bottle

Picture of Prepare Your Bottle

The first thing to do is cutting your bottle at the right height.

You have to cut 2-3 cm (about 1 inches) over the point where the bottle becomes thinner (the grip).

Use your scissors for that, or a Dremel if you have one! :)

You don't need to be super precise, but try to make a straight cut.

Now you have 2 separated pieces.

Easy, isn't it? :)

To the mixture!

Step 3: Mixture

Picture of Mixture

Now, put 200ml (6.75 oz) of tap water in a pot and boil it for 10 minutes.

This will eliminate the possible presence of chlorine.

Don't boil more thank 10 minutes, or too much water will evaporate.

While water is still hot, add 4 spoons of white sugar and mix until everything will be dissolved.

Now wait until water is at room temperature.

It's important, or high temperatures will kill the yeast and deform the plastic bottle.

Then, pour the sweety mixture in to the big part of the bottle (obviously).

Finally, add the brewer's yeast.

Don't mix yeast! If you do so, the reaction that attracts mosquitoes will NOT last longer.

Now that the mixture is ready, put the top part of the bottle inside the big one, face down, to create a funnel (the picture shows it well).

Finally, close the border with some tape to fix it up and make te cap hole the only way in-out for mosquitoes.

I've used black tape for electrical work, it's good for this kind of fixing.

Step 4: Prepare for Hanging

Picture of Prepare for Hanging

This step is optional, but I highly recommend it.

You can finish now your trap by wrapping the bottle with black cardboard to add a sun protection (not from the heat but from UV).

But, if you want a more stylish solution, I suggest the use of a liquor can container (the Baileys one is very popular).

Use a drill to open two holes near the top of the can, in opposite directions.

This holes will be used to create a knot with some string and use this can as a "hanging bottle container".

You will have a easy and quick way to change bottles without the need to take them down from hanging every time!

A bottle case ;)

Plus, this covering will protect the bottles from UV sun rays.

Finally, you won't have to make holes on the bottle surface, making some precious CO2 to go outside (next step to discover why!)

Step 5: Ready for the Hunt!

Picture of Ready for the Hunt!

Now make a knot in the other hole of the can and hang your trap outside!

In your garden or in your balcony, the best place is a dark and humid one, not exposed to direct sunlight.

But, how does it work?

The brewer's yeast produce a small but continue amount of CO2, that, mixed with the high sugar amount in water, creates a smell that is irresistible for mosquitoes!

So, these little devils fly inside the small hole of the bottle cap and get stuck, with no way out except for the hole itself. The percentage of mosquitoes that fly out again from the trap is ridiculously low.

The cover (black cardboard or the can) prevents UV rays from killing yeast and stopping CO2 production.

Also, we use tape around corners to prevent CO2 from going out from the bottle in "high" quantities.

The amount of yeast (10gr) last for about 2 weeks.

After this time, you will have a bottle full of mosquitoes! :D

You can clean it and fill it with new mixture, or prepare a completely new one.

With the quick change hanging system, it will be easy to have a new trap in minutes! :D

You now have a 100% natural and green trap, with zero amount of poisons or other harmful chemicals!

Hope you'll like and help you from getting bit ;)

From Italy, this is Filippo

Ciao a tutti!


camtheterpsfan34 (author)2017-05-07

Bravo e grazie mille per questo. As someone married to a Ugandan with family in East Africa, where malaria is extremely prevalent, this idea is perfect. I am not sure how hard it is to find brewers yeast there but all the other materials are readily available. Anything to combat malaria would be beneficial. Thanks again for the contribution and in terms of the contests you entered, in bocca al lupo!

I am sorry pseudo science banned DDT world wide. That little thing accounts for 1 million unnecessary deaths per year in Africa due to malaria.

MtuBoy (author)camtheterpsfan342017-05-07

Hi Cam. East Africa is home to the best, traditional home-brewed beer. So, you can imagine the land has never suffered a yeast supply shortage since the beginning of time.

JoS86 (author)2016-10-07

Hi, I don't have any sugar in the house. Do you think honey would work as an alternative?

DISPENSER4HIRE (author)JoS862017-08-31

Sugar is sugar. Sugar, molasses, honey, agave nectar, corn syrup, etc. are all sugar.

AnAmerican (author)JoS862017-05-07

I could just prick my finger and squeeze the blood into the bottle - they seem to love that.

PattyP17 (author)AnAmerican2017-05-10

"I could just prick my finger and squeeze the blood into the bottle - they seem to love that."

Best comment yet.

SeanFeeley111 (author)AnAmerican2017-05-07

To paraphrase Boris Karloff, "Thank you for the blood, I never drink wine". What a clever idea you have, and please excuse my Dracula reference. Actually bats consume vast quantities of mosquitoes. Though it takes a while to attract bats, properly constructed and placed bat houses are incredibly effective.

KennethR14 (author)SeanFeeley1112017-05-08

Bats actually mostly eat moths - not mosquitos. Studies have shown that ess than 1% of a bat's diet is mosquitos.

tucats (author)AnAmerican2017-05-07

That's funny!

kuma.rhyu (author)AnAmerican2017-05-07

Blood is not an attractant for mosquitoes. They home in on the CO2 mammals breathe out and the body warmth to find their hosts.

PattyP17 (author)JoS862017-05-10

Yes, probably. I use honey with yeast instead of sugar to make bread, so I think so.

ArjanD6 (author)JoS862017-05-07

Yes that should work, just use 2
spoons more since honey contains a bit fewer sugars

KevinJ142 (author)2017-05-07

Got a better idea, Use the same trap but only a lil sugar and water. have a tube coming from inside your house that air or basically Carbon Dioxide will flow into the middle of the trap. So instead of wasting yeast, they will be attracted by the real stuff. Put a screen or like a filter so only CO2 comes out of your house but they dont get in.

DarrenO2 (author)KevinJ1422017-05-07

KevinJ142 - Can you make an instructable showing what you are saying? It sounds good but I need more info.

KevinJ142 (author)DarrenO22017-05-07

Just build it the way he showed you, add a lil sugar and water at the bottom.

Take like a rubber gas line, make a hole on the side about 2 inches up from the water. Hot glue a piece of screen over the bottle end and then glue the tube into the bottle. The other end has to go into your house somehow. Your house is filled with CO2, so when it escapes thru the house and out the top of the bottle, the mosquitos will go in the trap but are stupid and don't know how to get out.

DISPENSER4HIRE (author)KevinJ1422017-08-31

Why would you believe your house if filled with CO2?

the norm (author)KevinJ1422017-05-10

I think it would be easier and cheaper to get the yeast and forget about making holes in your house.

KevinJ142 (author)DarrenO22017-05-07

I'm not sure it will work, just thought of an improvement

PattyP17 (author)KevinJ1422017-05-10

Not very workable as you would have to be able to collect concentrated carbon dioxide to funnel it outside. Sounds like you would have to build a carbon dioxide concentrating machine. The whole point is to build something simple, cheap and quick that works with little expense or effort.

uapublicnyc (author)2017-08-22

This should work in my apartment. possible improvements would be to make it black, and even black and white striped, a pattern my outdoor mosquito magnet has.

Related tip: If you cannot remove puddles outdoors where mosquitoes will lay eggs -- eg rain filled cracks in boulders -- add a couple of drops of basic dish washing soap: it reduces the surface tension and the mosquito eggs will fall to the bottom. I used this at a summer house in Main built on the rocks, it works!

ZenoM3 (author)2017-08-02

Lots of different opinions here and it's no wonder. Mosquitoes are different on every continent. And some people naturally attract more than others and it has more to do with scent than CO2 - heavy breathing, or heart rate.

They each have different scents they are attracted to and target different parts of the body. They will all bite you anywhere, but the large majority of bites will be in one area for each type. Here in North America they tend to go for the arms, hands and neck most. In Africa the mosquitoes that carry Malaria go for the ankles. On that continent people with stinky feet get bitten more often. They use stinky Camembert cheese to lure them into traps and away from sleeping areas.

gavinnn (author)2017-05-07

The most you can hope for, even if you fill your trap 5 times a night, is a warm feeling of revenge. As another poster said, there are billions of mosquitos, especially in your area, and your trap will not change the number of mosquitos landing on you - at all. Not criticizing, like your idea - easy to make and clever - just trying to add some perspective.

dcp123 (author)gavinnn2017-05-07

I could be wrong, but I don't think that's entirely correct. It is my impression that most mosquitoes don't travel far from where they hatch. If I'm right about that, you should be able to reduce the local population density around your house.

qb8546 (author)dcp1232017-05-07

This week I looked into a professional service. They said mosquitos travel up to 100 yards. That means the source can be somewhat far away.

ZenoM3 (author)qb85462017-08-02

they travel between 7 and 10 kilometers. Professional services say 100 yards because they sell products with 100 yard range being an affordable application. Source science books, not salesmen. ;)

gavinnn (author)dcp1232017-05-07

I did a bit of reading and this informative faq from the American Mosquito Control Association (Note: How far can mosquitos fly? What can homeowners do to reduce mosquito bites? and Are backyard systems effective? among others). It seems mosquitos ranges vary quite a bit, many around 150m according to the first article and up to, with some exceptions, around 11km (7mi). Hatching areas near the house do seem to provide many of the mosquitos we deal with, though, so it's worth dealing with them. The original poster is located not far from the massive swamps south of Venice, so he's prolly better off using barriers or repellants.

dcp123 (author)gavinnn2017-05-13

Thanks for doing the research I was too lazy to do. My prior understanding and experience with mosquito attacks near breeding locations is more consistent with few ranging more than 150 meters, but I have done no reliable studies and as your research indicates, it would not be at all surprising if their range of travel varied hugely. Also, as you point out, if some one is in the area of a massive mosquito source localized trapping will be less effective than if they have small sources nearby.

AndyMoore made it! (author)2017-06-18

Made a variation without the protective cover (just used some old masking tape). Great idea and quick build. So far, not catching any mosquitoes, but will be interesting to see what I catch. Thanks!

FrugalNana (author)2017-06-04

I am new, 64 and have a large infestation of mosquitoes. I have a stagnant creek behind my land. The comments are very good and I'm grateful for your tips. A few things for sure work well. Catnip is a of the mint family. I have made a spray with it, I added alcohol, so .. Even by rubbing it all over my skin and and clothes works awesome!. This has been very successful! All mints are great. Lemon smells work well too. I have onions and garlic growing also in my garden. If there's a mosquito, it finds my family. I plan to use the bottle tip. Many say it works. I love the fan too. I have seen a screen put on the back of the fan to catch them. Spray them withalcohol to kill them.. Hope this helps you.

Bhenley3 (author)2017-05-07

High winds like a fan is the only way to stop them from sucking your blood. Point it right on you and enjoy the outside in that one local spot. Nothing will work except for this.

katbow (author)Bhenley32017-05-08

Actually, you can keep them from even wanting to land on you, by eating raw onions...I've been in clouds of mosquitoes after eating a sandwich with a large, bread sized slice of, sweet purple onion. Everyone else was covered in bites but I didn't even have one.

OculumForamen (author)katbow2017-05-11

A friend oof mine used to take Garlic capsules, one every day during insect season, and he swore by it, and I did notice that he suffered FAR fewer bites than I did, when we went fishing. I live in Canada, and I can tell you that the Mosquitoes in the North are the territory's official Bird! We tried to use AA installations to control the Mosquito population, but last year they flew off with one of our guns, so we have abandoned this idea! LOL Seriously though there are a number of herbs that work as a mosquito repellant. The most powerful of them I have heard, is actually Cat-Nip! If you own cats, though, that would be a serious problem. Cat-nip in it's concetrated form, is on order of 100X more effective than DEET!

sleeepy2 (author)OculumForamen2017-05-29

No, I grew and used catnip. DEET is much more effective.

OculumForamen (author)sleeepy22017-05-30

Yes, actually. Google it. Catnip contains nepetalactone, which is 10 times more effective as a mosquito repellant than DEET. DEET disolves car paint! I used it every day when I was a teenager riding with my dad for work, and it softened the paint on the inside door sill where I always rested my arm, to the point I could scrape it off with my fingernail and it would take it right down to the metal! If you use a lab still and a hydro bath condenser, you can harvest the oils from the cat nip, and add it to a cream or a water spray and use it that way. Just growing catnip and rubbing it on yourself will not work. It's really not that hard, you just need to know the basics and have the components for a lab still. :)

ZacharyD41 (author)OculumForamen2017-05-24

The joke in maine is our other official state bird is the mosquito lmao

CindyL2 (author)katbow2017-05-12

Well, onion didn't work for me. Neither did garlic. I have tried numerous ideas. I am a mosquito magnet. I will try this on my porch. If nothing else, I can enjoy some Baileys.

jim1824 (author)katbow2017-05-09

Actually, I think eating a raw onion will keep everyone and everything away.

PattyP17 (author)jim18242017-05-10

LOL! Thumbs up.

w6pea (author)2017-05-16


I sure hope this works

JumpingThrghHoops (author)2017-05-14

So just to complicate things lets say the people with the CO2/tube idea use the tube and insert a needle into their own arm, and take their own blood and let it slowly drip into the bottle trap while watching t.v. Yes, that sounds right. ;-)

gavinnn (author)2017-05-13

No worries dcp123, it was totally self-motivated :) I live near water and my wife attracts more mosquitos than most traps do, so I'm always on the lookout for solutions!

CarolM131 (author)2017-05-07

Fruit flies love this also. In the U.S. we call this yeast Baking Yeast. Great idea- thank you!

CindyL2 (author)CarolM1312017-05-12

Actually it's not Baking Yeast, they are two different products. Baking yeast is used to rise bread, Brewers Yeast doesn't, I use it a lot for cooking, kale chips, sprinkle on pop corn. I love it. They are related, but brewers yeast is in a different "state", the live yeast has been dried and deactivated. So anyone with Candida problems should be able to use Brewers yeast without a problem.

I live in the US. Any store should carry it.

PattyP17 (author)CarolM1312017-05-10

I've successfully used apple cider vinegar in a trap like this for fruit flies and gnats. Fruit flies like bananas a lot too. And old saying:

Time flies like the wind. Fruit flies like bananas.

tnormandale (author)2017-05-07

Nice idea. I have actually found an effective control for mosquitoes is a large half wine barrel full of water. This attracts them, they lay their eggs their and when it is thriving with larvae (about once a week) I hit it with a dose of hypochlorite (about a third of a cup of the dry powder for chlorinating pools). This kills off the whole batch of larvae. I have only seen two or three mosquitoes all summer, compared with previous where twenty to thirty would attack you every time you went out of an evening to water the garden.

kz1 (author)tnormandale2017-05-08

I had a large plastic tote with 200+ gallons of water I used for electrolysis. Skeets love it when the current wasn't running through the water. Let 'em lay their eggs and hatch into wigglers, then turn the current back on. Given a whole new meaning to the term wigglers! :-)

GuyB12 (author)kz12017-05-12

> kz1


Definitely the funniest reply yet. Good to see you are in touch with the vicious side of nature. Gotta try this myself.

JerryK48 (author)2017-05-07

Teaspoons or Tablespoons ?

kuma.rhyu (author)JerryK482017-05-07

Probably teaspoons, but the proportions are not critical for this mix. The sugar is a food for the yeast to produce CO2 and attract the mosquitoes, making them think they are around a breathing mammal and a blood meal. If your trap does not produce well, try adding a little more sugar to the mix.

About This Instructable




Bio: Hi everybody! I'm Filippo from Bologna, Italy! My friends call me Orso (Bear) :) I follow Instructables since 2009, and it has always been one ... More »
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