Mosquito Dunks are one of the most efficient, long-lasting and easy-to-use solutions when it comes to getting rid of mosquito larvae.


  • Kills mosquito larvae in a matter of hours
  • The effect lasts for 30 days
  • Simple and easy to use
  • Safe for humans, animals and plants alike


  • Works only when placed in standing water
  • Doesn’t work on adult mosquitoes


Buy on Amazon

We review a lot of products and product groups on this site, and when we do, we always try to give you the most extensive information possible. We research all scientific and official sources and sift through hundreds of reviews and articles to deliver you the best possible review of the product. This time, however, we went a step further. We actually purchased the Mosquito Dunks and rigorously tested them for months, to make sure that we are giving you a truly independent, bias-free and comprehensive review of them. Because, although there is a lot of information on Mosquito Dunks available online, in this review we are doubling down on it and answering every conceivable question about Mosquito Dunks that you might have in hopes of satisfying all of your review needs. So without further ado, here is our review of the Summit Chemical Mosquito Dunks.



Mosquito Dunks, which is a registered trademark of Summit Chemical Co., are made almost exclusively out of a naturally occurring soil bacteria called Bacillus thuringiensis, more specifically its strain israelensis (aka B.t.i.). Each Dunk is about 2 inches in diameter, the size of a small cookie, and has a narrow hole in the middle to make it easier for you to keep them in place (using a piece of string, a piece of wood or other similar methods) and to prevent them from being flushed out of the area that they are treating.

As Zach Cohen, the Vice President at Summit Chemical Company told us, it all started in the 1980s: “B.t.i. was discovered in the Negev Desert in Israel in 1976 by Joel Margalit, a Professor at the Ben-Gurion University. Summit had a relationship with Dr. Margalit and in the early 1980s began working on a professional formulation using this novel bacteria.” Which resulted in the creation of the Mosquito Dunk predecessor Bactimos Briquets (now the Summit B.t.i. Briquets). They were then sold to different mosquito control organizations, who distributed them to the general public. However, the product became so popular and Summit received so many questions on where could people purchase these mosquito larvae-fighting briquets that they decided to create their retail brand. So the Mosquito Dunks brand was born, and “for the last 30 years the product has become the staple for biological, environmentally conscious mosquito control.”

In terms of their appearance and texture, Mosquito Dunks are solid, dry and rough, without being crumbly or brittle. And since they are made out of B.t.i., granular cork bark and a plaster compound they are also pretty light in weight, which allows them to effortlessly float on the water’s surface, where they can slowly dissolve and release the B.t.i. in the most efficient way possible. They also have a very light scent that remains unnoticeable in the water or when you are holding or storing the dunks.

Since Mosquito Dunks are made out of a naturally-occurring soil bacteria they, indeed, are eco-friendly and can be used for organic gardening as they are approved by the United States Environmental Protection Agency (U.S. EPA). To quote Zach Cohen: “This is a product that was “green” before eco-consciousness was even a common concept.” And because Summit is a US-based family-operated company, they produce their products exclusively in the United States of America, in their Baltimore facility. So Mosquito Dunks can also be labeled local. Yet, that doesn’t stop the manufacturer from providing the Dunks to people outside the US, seeing as the product doesn’t contain any harsh chemicals or substances that might be banned in some countries.


If you plan on purchasing your Mosquito Dunks online, you might be wondering if they can arrive damaged. And from our own experience, the answer is yes. The plastic packaging of the Dunks that we received was a bit dented upon arrival but the Dunks inside were intact. More importantly, however, even if they were physically damaged and broken into pieces, they would have still been usable and effective at treating the water containers they are put into, since it’s even recommended to break up the Dunks if you want to treat an area that is smaller than the recommended 100 square feet of surface water. So, you shouldn’t hesitate to purchase Mosquito Dunks online if their delivery is what worries you.

As for the packaging itself, the Mosquito Dunks came in a standard, commercial plastic packaging, so, while the Dunks themselves are eco-friendly, the packaging is less so. However, Summit has made strides in making their packaging more eco-conscious. The plastic part of the packaging is chlorine-free, while the back part of it is paper and therefore can be easily recycled. And the sturdy nature of the packaging also means that the Dunks can safely travel to your home and that you won’t be paying extra just for the package of the product.

When it comes to the volume of the Dunks, you generally have a choice between 3 different package sizes – 2, 6 and 20 Dunks. If you just want to test Mosquito Dunks for yourself, buying a small package of 2 Dunks is advisable. However, since Mosquito Dunks need to be replaced every month, buying a pack of 20 Dunks is the best and most cost-efficient long-term option.


How do Mosquito Dunks fair price-wise compared to other similar insecticide options? As far as traditional insecticides are concerned, Mosquito Dunks are incalculably more efficient at killing mosquito larvae. A single Dunk dropped in a water container infested with mosquito larvae can kill thousands of future mosquitoes before they’ve even had the chance to take flight. So much so that simple mosquito sprays and repellents might seem almost pointless compared to the level of effectiveness of Mosquito Dunks.

And the convenience of the Dunks and their longer-lasting effect also make them ideal for use over other similar products. Mosquito Dunks can be more easily anchored via a string, they last longer, need to be replaced less frequently, and they are more practical to use in larger, open water basins since one single dunk can treat up to 100 square feet of surface water which is about the size of a standard-sized single garage.

How do Mosquito Dunks work?

Mosquito Dunks work by gradually releasing their natural larvicide in the water they’re in. The mosquito larvae then simply feed on the B.t.i. larvicide and die from it in a matter of hours. There have been plenty of scientific and laboratory experiments and evaluations on the effectiveness of Bacillus thuringiensis subspecies israelensis on insects such as Aedes aegypti aka the yellow fever mosquito and Aedes albopictus aka the Asian tiger mosquito. And it’s undeniably clear that Mosquito Dunks work perfectly against all 2,500 different species of mosquito larvae, as well as on insects like fungus gnats and black flies. However, there is zero evidence that it works against other creatures, including other insects and bugs. So if you’re worried that you might hurt your local bee, dragonfly, ladybug or other beneficial insect population, then there is no reason to be concerned about that.

To take a deeper look into the chemical facts about B.t.i.’s effectiveness, we’d suggest this extensive study on the NCBI.

While mosquito larvae that consume B.t.i. die pretty quickly, in a matter of hours, you can expect to start noticing a diffidence in approximately 2 days and see the full effects of the larvicide in about a week. Since it kills larvae only and not adult mosquitoes, you’ll still have to deal with the already existing adult insect population or just wait for them to die off. Yet, once this is done there should be no further mosquito generation and any adult mosquito that comes from outside of your immediate environment and tries to populate the waters you’re treating with the Dunks, is bound to fail.

And since adult mosquitoes don’t realize what’s happening to their offspring they will keep trying to repopulate in the larvicide water and therefore will effectively doom their own offspring to death.

With each Dunk lasting 30 days and treating 100 square feet of surface water, using Mosquito Dunks will let you cheaply and easily exterminate countless future adult mosquitoes before they even developed their wings.


Mosquito Dunks are very easy to use as all you need to do is place the correct amount of the Dunks to the appropriate amount of water – one Dunk per 100 square feet of surface water. The depth of the water container is irrelevant because as Cohen explained: “In order for the mosquito larvae to consume the active ingredient it must be released at the water’s surface where larvae generally feed.”

So if you have a water container that has a surface area of about 25 to 100 square feet, float a single Dunk in the container and you should be mosquito larvae-free for a whole 30 days. If you have a water body of larger surface area, a large pond, for example, use two or more Dunks. While if you have a smaller container that collects water and that you want to treat, then break up the Dunk and use only as much of the Dunk as you need. One half of the Mosquito Dunk will treat about 5 to 25 square feet of surface water and a fourth – 1 to 5 square feet of surface. Just remember, that there is no point of using more than one Dunk in the recommended water surface area since it will do nothing but waste the product. The exception, however, is if the water is highly-contaminated, then an increased dose of Mosquito Dunks might be of use.

Where to use Mosquito Dunks?

You can use the Mosquito Dunks in anything that contains water and that can’t be drained or prevented from accumulating water – rainwater barrels, ponds, tree holes, flower pots, rain gutters, swimming pools, animal feeding troughs, septic tanks, water puddles, pet bowls, you name it. But if you already have chlorine in your swimming pool you won’t need a Mosquito Dunk since the chlorine prevents mosquito larvae from developing anyway. And pool filter and aeration systems also keep mosquitoes away since they circulate the water and keep the water from going stagnant.

As long as there is standing water, no matter if the container is outdoors or inside your home, the Dunks will do their job.

They are less recommended, however, for flowing water (rivers, canals, fountains with strong water circulation, and so on), since mosquitoes tend to ignore such water sources and since the Mosquito Dunks just wouldn’t be efficient in water that is constantly moving.

You can also place Mosquito Dunks in dry places such as your garden soil if you know there are heavy rains coming and the soil tends to retain moisture and form puddles (one Dunk to about every ten square meters of dry surface). This will make sure that mosquitoes don’t catch you by surprise by breeding in unexpected places like puddles for example.

When to use Mosquito Dunks?

In terms of when Mosquito Dunks should be used, the general rule is the sooner the better. Since they kill mosquito larvae its best to target the first annual breeding cycle of mosquitoes by applying the Dunks in early spring (March, April or even February for some parts of the Northern hemisphere). And continue to consistently use the Dunks all throughout the mosquito season.

So although the Dunks don’t have to be used in the seasons when mosquitoes aren’t active (for example in the winter) you do need to make sure that you are consistent with your Mosquito Dunk usage to truly make sure that no new mosquitoes are breeding in your area. And if you forget to use the Dunks one month or even for just a few days, don’t fret, place them in the water as soon as you remember and they should start killing mosquito larvae again within hours.

It doesn’t matter at which time of day you use the Dunks, just whether you are using them regularly and whether you are employing additional mosquito control methods to combat the adult mosquitoes that live in your immediate area.

Other points to consider

There are also some steps you might want to take to preserve the Dunk’s well-being so that they can do their job.

  • Make sure that the Dunks don’t get washed out of the water by rainwater or wind, or caught in the weeds of your pond by anchoring them in the middle of the water using a stake, string or other similar methods.
  • Summit states that UV rays shouldn’t affect the performance of Mosquito Dunks, so the Dunks will be effective even if kept in direct sunlight for extended periods of time.
  • Also make sure that your pets, fish or other animals don’t eat them. All mammals, birds, and amphibians will be one hundred percent fine if they consume the Mosquito Dunks, but this will simply prevent the Dunks from doing their job. Therefore make sure to keep the Dunks in a protective stocking that allows water to pass through if animals frequent the place that you are treating with the Mosquito Dunks or especially if you have fish or turtles as they love to consume them.
  • Additionally, make sure to keep in communication with your neighbors, tell them about Mosquito Dunks and ask them to use the Dunks as well. This will make sure that not only the area that you actually own is free from mosquito larvae and therefore from mosquitoes. But that mosquitoes aren’t breeding nearby and then flying to your backyard and continuing to bother you since mosquitoes usually hang out in one to three-mile radius.
  • And finally make sure you need to use as few Dunks as possible, Meaning, remove all the standing water from your property that you can. There is no point in dipping Dunks in water containers every month if you can simply get rid of the water itself. And with things such as flower pot containers or dog bowls, for example, remember to change their water at least twice a week to prevent the mosquito larvae from maturing in the water.


As Mosquito Dunks are generally safe for humans and other animals, there are very few safety guidance tips you’ll need to follow when using this product.


You can freely use Dunks in and near soil you use for growing fruits and vegetables as it will not affect their taste or healthiness in any way. You can also water your plants with water that has been treated with Mosquito Dunks, no matter if it is rainwater, water from a well or any other source because the Dunks won’t do any damage to the plants or to you if you consume the plants that have soaked up the Dunk water. And Mosquito Dunks can even be placed in plant pots that retain water because they won’t do any harm to the plants growing in the pots nor to the soil in which the plants are growing.


When it comes to animals and other living organisms, Summit Mosquito Dunks are, in fact, safe for all organisms. This includes all animals from pets (cats, dogs, etc.) and livestock (cattle, horses, sheep, etc.) to wildlife (deer, foxes, rabbits, etc.). All birds from poultry and other domestic ones (chickens, turkeys, geese, etc.) to wild birds. All aquatic life no matter if these aquatic organisms are living in aquariums, ponds, lakes, terrariums or other water reservoirs (tadpoles, turtles, fish, reptiles, etc.). As well as all insects and bugs except mosquitoes, black flies and fungus gnats, including pollinators like bees and other beneficial insects. So nothing bad will happen if Dunks will be used in habitats of any of the aforementioned entities. Or even if Dunk-treated water seeps in the nearby lake, pond or any other environment inhabited or frequented by animals, birds and other organisms.


And Dunks are even completely safe to humans. If you or your child accidentally consumes a Mosquito Dunk or drinks water that had Dunks in them nothing bad will happen. This includes rainwater and groundwater that has been dosed with one or more Dunks. However, you should avoid putting Mosquito Dunks in treated drinking water. Although B.t.i., the main ingredient of Mosquito Dunks, is safe for us, you shouldn’t drink it in large amounts, because it means that you will be constantly consuming large doses of protein and calcium which can be harmful to some people. Besides, if you put the Dunks in your drinking water you would essentially be wasting them since you would just consume the water as well as the B.t.i. without allowing it to do its job of killing mosquito larvae that are in the water.

Mosquito Dunks are safe for all humans and animals, as well as plants and other living organisms.

They also won’t damage any mechanical equipment that you might have in the water that you want to treat with the Dunks. Since they are quite brittle and dissolves over time Dunks won’t clog your water filter, fountain pump or damage other things that you might have in the water like pond thermometer, light fixtures or statues. And you can even wash your car with water that has a Dunk floating in it because the paint of your car will be totally safe and damage-free. Just don’t go using the Dunks as water filters, because although they might look like a water filter, they do not serve this purpose.


Standard Mosquito Dunks have 2-year (24-month) shelf life which is typically plenty of time to use them up since the largest packs have 20 Dunks in them and each Dunk lasts just 30 days.

Handling the Dunks

Although you do not need to wear gloves, safety goggles, a respirator or any other safety gear when handling Mosquito Dunks you should avoid getting the Dunk particles in your eyes or your skin. Yes, Dunks are perfectly safe for humans, however, the tiny particles of the dunks, dry or wet, can still irritate your skin and eyes, especially if you are sensitive to different irritants. So if you don’t want to experience any physical irritation, handle the Dunks with care and wash your hands right after.

First aid

What to do if a piece of the Dunk happens to get into your eye? Thoroughly rinse the eye with running water for about 15 minutes and you should be good to go. However, if the irritation persists you should contact your doctor. While if you accidentally swallow a piece of Dunk or water that was treated with a Mosquito Dunk, nothing needs to be done. It won’t do you any harm. Yet, there might be a slight irritation for some people, and if that happens to you, again call your doctor for advice.

Storage and disposal

When stored, Mosquito Dunks should be kept in dry, cool and well-ventilated area, away from direct sunlight or heat as they can cause the Dunks to deteriorate quickly. Aside from that, there really aren’t any more specifics about storing Summit Mosquito Dunks. Just make sure your pets or kids don’t find them as they can eat or ruin them pretty quickly too – the Dunks will be harmless to the kids or pets, but they’ll just go to waste if they are chewed up by your dog or ruined by your little one.

And as far as disposal is concerned, Mosquito Dunks are a natural and eco-friendly product so you can dispose of them however you like. The packaging of the Dunks, however, isn’t. It’s made out of non-biodegradable plastic, so be mindful when disposing of it.


Make sure you use additional mosquito control methods together with the Dunks as they won’t interfere with the Dunk efficiency, rather these methods will help you get rid of all the mosquitoes, not just their larvae.

For example, you should remove as much of the standing water on your property as possible so that you don’t have to use the Dunks all over your backyard. You can also use window and door screens to keep the mosquitoes out of your home. EPA-registered insect repellents will help you deal with adult mosquitoes and keep them from biting you while you’re outdoors. And the usage of various yard treatments is also beneficial since it will ensure that your outdoor space becomes a mosquito-free zone.

And remember, as long as the Dunks are dipped in standing water, they will do their job of killing mosquito larvae, no matter how you combat the adult mosquitoes above the water. So employing some additional mosquito control methods on top of using mosquito dunks on your property will only help you get rid of all mosquitoes quicker.


Using Mosquito Dunks is one of the best ways how to deal with your mosquito larvae problem because they will kill the larvae in any standing water in a matter of hours and will keep the water larvae-free for up to 30 days. So why not kickstart your mosquito larvae treatment with a solution that even professionals recommend?

Buy on Amazon


Mosquito Dunks containing Bacillus thuringiensis subspecies israelensis are a safe and natural way to kill mosquito larvae before they have a chance to flourish into adult mosquitoes. In words of Summit’s Vice President Zach Cohen, Mosquito Dunks were built to be a non-toxic, green and eco-friendly product “through the use of natural ingredients safe for everything except the targeted true flies”. You can use them in any container of standing water with little to no concern of your or your kids’, pets’ or your own safety, as Mosquito Dunks are harmful only to mosquito larvae, fungus gnats, and black flies. And they are both effective and efficient, while also working great in conjunction with other anti-mosquito products and methods. So why not try them out and see your mosquito population diminish before your very eyes?


What are Mosquito Dunks?
Mosquito Dunks are small, donut-shaped, floatable larvicide product that dissolves in water and kills mosquito larvae.
How do Mosquito Dunks work?
Mosquito Dunks release a bacteria (Bacillus thuringiensis israelensis aka B.t.i.) in the water. And once the mosquito larvae consume this bacteria, it enters the stomach cells of the mosquito larvae, where it paralyzes their gut and forces the larvae to starve to death.
What are Mosquito Dunks made of?
They are made out of a natural bacterium called Bacillus thuringiensis subspecies israelensis. (B.t.i.). It’s a natural bacteria found in soil. And while it’s lethal for mosquito larvae, it’s safe for other living things.
How long do Mosquito Dunks last?
A standard Mosquito Dunk will last about 30 days in approximately 100 square feet of surface water.
How to use Mosquito Dunks?
To properly use a Mosquito Dunk just drop an appropriate amount of the Dunk in the water and let it go to work. If need be, you can use the hole in the middle of the Dunk to keep it in place.
Do Mosquito Dunks work?
After going through a lot of scientific data, as well as conducting our own tests, we can categorically state that, yes – Mosquito Dunks do work and are efficient at killing mosquito larvae.
Which should you choose – Mosquito Dunks or Mosquito Bits?
For an immediate, short-term effect use Mosquito Bits. However, for a slightly slower but a more prolonged effect use Mosquito Dunks.
Where to buy Mosquito Dunks?
You can purchase Mosquito Dunks both in various stores or order them online from such retailers as Amazon, Home Depot, and others.
How to use Mosquito Dunks for fungus gnats?
Sprinkle pieces of a broken up Mosquito Dunk on the infected soil and pour water on top of them. Repeat the process in about a week.
Are Mosquito Dunks safe for swimming pools?
Yes, Mosquito Dunks and the water treated with them are 100% safe for both humans and other living creatures including pets, fish, etc.
Are Mosquito Dunks safe for kiddie pools?
Yes, Mosquito Dunks are just as safe for children as they are for adults.
Are Mosquito Dunks safe for pets?
Yes, even when consumed directly, Mosquito Dunks will be nothing more than a dose of protein and calcium for your pet.
Are Mosquito Dunks safe for dogs?
Yes, dogs, cats, as well as other pets and mammals won’t be in any way affected by Mosquito Dunks, even if they happen to consume them directly.
Are Mosquito Dunks safe for bird baths?
Yes, Mosquito Dunks are totally safe for birds and therefore can be used in bird baths.
Are Mosquito Dunks safe for birds?
Yes, Mosquito Dunks are harmless to birds.
Are Mosquito Dunks safe for fish?
Yes, Mosquito Dunks are completely harmless for fish even when consumed directly.
Will Mosquito Dunks kill tadpoles?
No, Mosquito Dunks are safe for tadpoles, as well as other amphibians.