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Summit Mosquito Dunks Larvae Control Tablets, 20 count

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About This Item

Details

  • Mosquito dunk spreads a bacterium that kills larvae before they grow up to become biting adults.
  • For use in any standing water including rain barrels, bird baths, koi ponds, tree holes, stock tanks, planter reservoirs and rain gutters.
  • Deadly to mosquito larvae but harmless to other living things with the active ingredient Bacillus thuringiensis subspecies israelensis (Bti).
  • When females lay their eggs in water treated with the dunks, the larvae will hatch and eat the bacterium.
  • Each dunk covers up to 100 square feet of water, regardless of depth for 30 days or more; for less water a portion can be used.

Instructions

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Questions & Answers

18 Customer Questions

Not intended to be ingested but can put it in animal water trough. Which answer is correct?

Answer by Patty • Jun 08, 2026
Yes

Will this harm my water turtles and goldfish that are in my small pond?

Answer by Chewy • Nov 26, 2019
This product can be used in your pond and it will not harm other living things such as birds, wildlife, children and pets.

Can this be put in a 3 gallon dog water bowl? Will it hurt dogs?

Answer by Chewy • Mar 18, 2018
This is not intended to be used in a drinking water bowl, and is not intended to be ingested.

can i put these in my horses waterer?

Answer by Chewy • Aug 16, 2019
This dunk can be used in animal watering troughs.
Reviews
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4.6
Rated 4.6 out of 5 stars
313 Ratings
Terms & Conditions

127 Customer Reviews

Rated 5 out of 5 stars
Verified Purchase
By Pam on Jul 7, 2025

These work great! No more mosquitos!

Our son had tried these at his new home. We were there for a family swim party and there were no mosquitos! He told us how he put pine straw, grass clippings and

Our son had tried these at his new home. We were there for a family swim party and there were no mosquitos! He told us how he put pine straw, grass clippings and water in 5 gallon buckets with one to two of the donuts per bucket. My husband used these around our home and barn. It takes a couple of weeks but when it started working, it did the trick! We sat at our pool deck with my daughter and grandson swimming all evening and never saw one mosquito! A few weeks ago it was a different story without the mosquito dunks! We all had bites and could actually see the mosquitos landing on us! The same was true at our barn, around where we tend our backyard chickens. It’s all clear up there as well. We would highly recommend this product! It works!

Rated 5 out of 5 stars
Verified Purchase
By Candy on Jan 3, 2026

Worked wonders in TN!!!

Our neighbor has a large pond right next to our backyard. It is over grown and they do not treat it. The mosquitoes are Terrible. We have tried these for 3 summers

Our neighbor has a large pond right next to our backyard. It is over grown and they do not treat it. The mosquitoes are Terrible. We have tried these for 3 summers. The first two we used them for 2 months and forgot about them. The mosquitoes were horrendous. Even for the neighbor on the other side of us. My husband did not believe they worked at all. This past summer I was determined to see if they would work all summer if we treated on a monthly basis. So we treated from May to October. I bought the granules and the dunks. We walked around and threw handfuls of granules onto the water as far as we could. This gave it a quicker start. Then also threw in the dunks. Treated every month like clockwork. these things did wonders!!! They made a huge difference! The other neighbors mentioned they didn’t have any mosquitoes this year. It takes a bit to work but patience pays off in the end. It is cheaper than paying for fogging and we don’t have to breathe poisonous chemicals.

Rated 5 out of 5 stars
Verified Purchase
By Carol on Mar 17, 2025

These work well

We live out in the country. We put dunks in pails of water and sit the pails in inconspicuous areas around the outside of the house. We like it that the water and

We live out in the country. We put dunks in pails of water and sit the pails in inconspicuous areas around the outside of the house. We like it that the water and dunks in the pails is not harmful to any other animals. As long as we keep water and a dunk in each pail, we hardly have any mosquitoes.

Rated 5 out of 5 stars
Verified Purchase
By ZsaZsa on Nov 27, 2017
Top 500 Contributor

I use these in multiple aquariums

I bought these in the hopes that they would work on caddisfly larvae and they did! In less than a day they were all deceased. I researched the main ingredient and

I bought these in the hopes that they would work on caddisfly larvae and they did! In less than a day they were all deceased. I researched the main ingredient and found it is useful for many creepy crawlies so I would suggest conducting your own research if you keep any invertebrates, as I am unsure if it would affect them as well. They crumble a little bit and I think they are made of cork. To keep my aquariums pretty I just place a chunk of dunk behind the mechanical filter media. In my koi pond I just toss one in. A greedy fish actually ate a piece over a month ago and he's still doing fine lol.

Rated 4 out of 5 stars
Verified Purchase
By Catherine on Aug 22, 2026

Finally helping our yard

Our yard is riddled with mosquitoes, and it's nearly impossible to spend any amount of time out there in the summer without being eaten alive. This summer we are

Our yard is riddled with mosquitoes, and it's nearly impossible to spend any amount of time out there in the summer without being eaten alive. This summer we are attempting to control it with mosquito dunks. We started a little later in the season than is recommended, so our results have not been perfect, but I'd be lying if I said I didn't notice some distinct improvement. We have a couple buckets set out at the perimeter of our yard, and when we are outside on our direct patio, we don't typically see many mosquitos.. maybe get a couple bites, but much better than the dozens we'd usually wind up with. The closer you get to the buckets, the worse it is, though. So really, do not put these buckets near any space you plan on spending time.

Rated 5 out of 5 stars
Verified Purchase
By Christine on Sep 17, 2020

Killed Larva in Drains! Yeah!!

We have large drainage system in our yard and found we didn't have as many fleas in our grass as we had mosquito larva in our drains. 20 bites on my legs in the

We have large drainage system in our yard and found we didn't have as many fleas in our grass as we had mosquito larva in our drains. 20 bites on my legs in the hour I was out playing with our dogs...they were getting bit too, but I couldn't find fleas on them! We sprayed our yard and still got bit. Well I ordered these little donuts, followed the directions and we do not breed mosquitos any longer. Wonderful stuff. Keeps our drains from being a breeding ground.

Rated 5 out of 5 stars
Verified Purchase
By Beatrice on Aug 25, 2025

I used these to make Mosquito Bucket of Doom for the yard

I added a quarter of a dunk to a 5-gallon bucket with a little leftover hay to make it release some carbon dioxide to attract mosquitoes. I have seen a noticeable

I added a quarter of a dunk to a 5-gallon bucket with a little leftover hay to make it release some carbon dioxide to attract mosquitoes. I have seen a noticeable reduction in the number of mosquitoes, and haven't been bitten in quite awhile, so I believe this has been very helpful.

Rated 5 out of 5 stars
Verified Purchase
By Robin on May 18, 2021

Love this stuff

I love the mosquito dunks! I throw some fresh ones in our pond once a month and it keeps my yard free of mosquitoes! Each spring we have an onslaught of mosquitoes,

I love the mosquito dunks! I throw some fresh ones in our pond once a month and it keeps my yard free of mosquitoes! Each spring we have an onslaught of mosquitoes, and that’s my cue to start my routine, they slowly diminish and at around one month later they’re gone for good (as long as I stay on the routine) They say on the label that they kill nothing but mosquitoes, and I love that!! I don’t want to hurt my fish or any other form of nature :)

Rated 3 out of 5 stars
Verified Purchase
By Nancy on Apr 5, 2022

Breaks up too easily clogging my fountain pump.

I read the reviews on this and thought I would give it a try on my 3-tiered barrel fountain. The instructions guide you as to how much to place in the water so

I read the reviews on this and thought I would give it a try on my 3-tiered barrel fountain. The instructions guide you as to how much to place in the water so I broke the ring into quarters and placed one piece in the bottom base of my fountain. It floats on top of the water and began breaking up into little "beads". I cannot verify whether these are working when my fountain pump is off during the night or not because I have seen many mosquitos flying around near the fountain during the morning hours. Also the beads are clogging my pump. I like the fact that they are harmless to fish/birds/etc., but will give it time to see the end results. They are fine in my bird bath but I never had an issue with mosquitos in that anyway as I change the water frequently and have a spray for that. I am on the fence with these but have the entire package to see actually if they work through the summer months. I will update my review if needed.

Rated 4 out of 5 stars
Verified Purchase
By Susan on Jun 19, 2025

They work!

We have had so much rain in our area that the water in our side yard isn't drying up. We are seeing lots of mosquitos which is unusual. I threw a couple of these

We have had so much rain in our area that the water in our side yard isn't drying up. We are seeing lots of mosquitos which is unusual. I threw a couple of these In to stop the breeding. So far, we aren't seeing the mosquitos like before.