Backswimmer Bite: Is it Poisonous? – Clearing the Myth

Backswimmers are unique aquatic insects known for their upside-down swimming style.

They are often found in freshwater ponds, lakes, and swimming pools.

While these insects are known for their fascinating appearance and behavior, some may wonder if their bite poses any danger to humans.

The backswimmer’s bite can indeed be painful, as the insect does inject venom during its feeding process on prey.

However, the venom is not dangerous to humans, except in very rare cases where an individual might experience an allergic reaction.

Backswimmer Bite

For the majority of people, the pain and discomfort from a backswimmer bite will subside within a few hours.

Comparing backswimmer bites to other insect bites, they are generally less worrisome than mosquito bites or venomous snake bites.

While it’s an unpleasant experience, a backswimmer bite is typically not poisonous or dangerous to humans, and simple first aid measures should alleviate any discomfort.

Backswimmer Bite: Is it Poisonous?

Pain and Reaction

Backswimmer bites can be quite painful due to the insect’s toxic saliva. The initial sensation may feel like a sharp, burning sensation at the site of the bite.

Some people may experience a more severe reaction if they are particularly sensitive to the toxin.

Toxic Saliva and Severity

Although the saliva is not considered poisonous, it can still cause discomfort.

The severity of the reaction can vary, but it should be noted that the bite is not life-threatening.


Treating a Backswimmer Bite

When treating a backswimmer bite, follow these steps:

  1. Clean the affected area: Use soap and water to prevent infection.
  2. Apply a cold compress: This helps reduce pain and swelling.
  3. Consider over-the-counter pain relievers: If the pain persists, consider using pain relievers such as ibuprofen.

Comparison Table

FeatureBackswimmer BiteHoney Bee Sting
Risk of Severe ReactionLowerHigher
Treatment DifficultyEasyEasy

Where Can You Find Backswimmers in Residential Areas?

Swimming Pools and Backswimmers

Backswimmers are attracted to residential swimming pools primarily for two reasons:

  • Artificial lights: These insects are drawn to the bright lights around pools at night. They have wings and can fly towards the light
  • Air bubbles: The presence of bubbles in the water may indicate a food source for backswimmers.

These pesky insects should be kept out of pools to avoid unpleasant encounters with swimmers.


Controlling Backswimmers in Your Pool

Here are some effective ways to manage backswimmers in your swimming pool:

  • Use pool covers: When not in use, cover your pool to reduce the attraction of artificial lights and to prevent insects from entering the water.
  • Maintain pool chemistry: Regularly monitor and adjust the chemical balance of your pool to deter backswimmers from breeding.
  • Remove debris: Clear out any floating debris and keep nearby vegetation trimmed, as this can be a potential breeding ground for aquatic insects.
Pool coversPrevent entry, reduce light exposureMay require manual installation
Maintaining chemistryDeters breedingConstant monitoring and adjustments
Removing debrisEliminates breeding groundsNeeds regular cleaning

Remember to keep an eye on your pool and its surroundings to maintain a backswimmer-free environment.


Backswimmers can bite humans if handled or disturbed. Backswimmer bites are not poisonous, but they are venomous.

This means that they inject a substance into the victim, rather than being ingested or absorbed by the victim.

The substance is a digestive enzyme that helps the backswimmer dissolve and consume its prey.

The enzyme can cause pain, swelling, itching, and redness in humans. Their bites can be treated with cold compresses, antihistamines, and painkillers.

Backswimmers are often found in pools near residential areas, and you should avoid contact with them by regularly cleaning the pool and maintaining the pool chemistry.

Reader Emails

Over the years, our website, has received hundreds of letters and some interesting images asking us about backswimmers.

Scroll down to have a look at some of them.

Letter 1 – Backswimmer

Backswimmer abdominal hairs
Location:  Santa Cruz Mountains
July 22, 2010 2:45 pm
Hello Bugpeople,
I saw a few letters concerning backswimmers and thought you might like to see this photo I took in my sister’s pool that inadvertantly captured extremely long hair-like structures on the abdomen of the backswimmer.

I’d never seen them before until I enlarged the photo. I assumed they would be for breathing (extracting oxygen directly from the water?), but apparently they just help hold the abdomen at the surface of the water.

Incidently, I tried my hand at raising a few chickens a couple of years ago. I learned that everything loves the taste of chickens: raccoons, coopers hawks, coyotes, etc.

I did manage to get a couple to egg-laying age, and had a nice run for a while (loved those fresh rich eggs), but eventually a wily coyote found his way into the enclosure and finished them off.

While they were here, though, they were the happiest chickens on the planet – a full half-acre to run around on, and I fed them termites and other pests when I encountered them.
Fellow Bug Lover Dave


Hi Dave,
Thanks for the great letter and wonderful images of a Backswimmer.  We will need to do a bit of research on the hair subject, but we didn’t want to wait to post your letter.

Thanks also for the tips on chicken predators.  We were very mindful of making the chicken coop very secure.  The chicken run is only four foot high chicken wire, but we don’t plan on letting the chickens out of the coop without supervision, at least until they are much larger. 

We will lock our chickens, we just named the gold one Ginger, into the coop each night which should keep them safe from nocturnal raccoons and owls, and coyotes that pose a greater threat at night. 

Our biggest fear is the hawks, especially Cooper Hawks which feed on the doves that come to our bird feeder.  There are also Red Shouldered Hawks and Red Tail Hawks in the neighborhood, but the smaller Cooper Hawks are the ones we are most nervous about.

Letter 2 – Backswimmer

Pool Bug (good backstroke) Central Kentucky Area
Great site! Thanks…if this *critter* is amongst your pages, I’ve missed it. Found in swimming pool, and can range in size from 1/4 in to almost 1/2 in in length.

Incredible swimmers, with legs that propel in water very quickly. Don’t think it comes up for air, but could be wrong….can stay submerged for long periods. Very awkward out of water…seems to “flip” around trying to make it’s way back.

I’m guessing it’s an immature common insect, but don’t have a clue. Any help in identification would be appreciated
Terry L

Hi Terry,
The reason you couldn’t locate your Backswimmer, Notonecta species, on our site is because it is a first for us. We actually had to make a decision where to put it. We decided the Toe-Biter page was the most appropriate location, and we will expand the scope of the page.

Backswimmers are True Bugs and they are torpedo shaped and aquatic, but fly. They propel themselves through the water up-side-down in a jerky erratic manner using the extended and hair-fringed hind legs as oars.

Air trapped in abdominal pockets enables them to remain submerged for six hours of inactivity if necessary. Their wings and backs are pale and the undersides are dark which acts as protective coloration while swimming.

They are excellent hunters that prey upon insects that get caught in the water, aquatic insects and tadpoles. They have piercing mouthparts and can bite. Thank you ever so much for adding something new to our database.

Letter 3 – Backswimmer

Diving water bug
These are in my swimming pool by the hundreds. They swim around and dive to the bottom of the pool, using those log legs in the back. What the #$%^! are they?

Hi Robert,
We see from your subsequent email that you have identified your Backswimmer and provided a link with information.

Letter 4 – Backswimmer

water bug?
I found several of these bugs in my pond (located in Northern NJ) while doing repairs to it today. It tends to swim to the bottom and bury itself under the rocks or it floats to the top.

They are all about 1 inch or less in length. Since restoring the pond last year (it was filled in 25 ago) several species have returned including this guy and I would like to know if it a pest or friend?

If it is a pest, what other insect, bird, etc can I attract to control them? Thanks!

Hi Mike,
This is a Backswimmer, a Water Bug in the family Notonectidae. They are predators that eat insects that fall into the water as well as aquatic insects, tadpoles and small fish.

Letter 5 – Backswimmer

Aquatic transformer bug…?
July 10, 2010
I found a bug very similar to Jason’s (of Folsom) bug. Only, mine was a bit fatter. It was the exact same circumstances too. I had just shocked my pool.
I found it coming out of one of the filters.

I swam about with two long legs, almost like how a frog swims. I thought to myself, “how the heck is this thing living?” Like Jason said, it must have had a serious chlorine tolerance. I scooped it out of the pool promptly.

It started to kinda writhe around and then began to try to walk with its two long legs. Then it stopped, like it gave up. I thought it had died, but to my amazement, it tucked its two long legs into itself, and its back sprouted wings, like how a lady bug does!

It didn’t fly very fast. It actually looked drunk. I guess it sniffed out the pool, because I watched it fly right back into it. As soon as it was underwater again, it tucked its wings back in, and shot out its two long “frog” legs, and swam away.

I swear to you that this is completely true. At first I almost thought it was an alien. This was 3 days ago, and I’ve been searching the pool since to try to get a photo or video, but I can’t find it again. Please let me know if you have any idea. I want to know if I can let my kids swim in the pool again.
Santa Cruz, CA


Dear Baffled,
The insect in your photo is a Backswimmer in the family Notonectidae.  Backswimmers are aquatic insects that can fly from one body of water to another. 

Since there are probably not many other insects to prey upon in your pool, we suspect that the hungry Backswimmer has probably relocated to more fruitful hunting grounds. 

Backswimmers, because they are capable of delivering a painful bite, are sometimes called Water Bees or Water Wasps according to BugGuide.

Letter 6 – Backswimmer

Boatman Pic actually Notonecta?
September 28, 2010
Hello, Friends of the Bugs,
While trying to ID a bug that had landed on our deck here in Edmonds,WA, I discovered that you have the same picture on your site under two different headings/labels. 

It comes up under “Water Boatman are Edible” when “Boatman” is typed into the search box.  Your answer to that post was to say it was Corixidae. 

The picture matches “my” bug exactly, and I had also come to the tentative conclusion after initially looking in Bug Guide, of Corixidae, but wasn’t convinced. 

However, on BugGuide I happened to see another pic that also matched, was mislabeled as Corixidae, and someone had posted that it was Notonecta.  Looking further online, I agree 100%.

If I type Notonecta or Backswimmer into your search box, it comes up with a post titled “Backswimmer” which appears to be the exact picture, this time correctly IDd as Notonecta. 

I thought you’d like to know so a note can be added (or however you want to deal with it, if at all) to the Boatman one, correcting the ID.  It might be confusing to some, such as myself, who might not accidently happen upon the correct ID and be thinking it is a Boatman. 

I think many folks, like myself, might initially do a search for Boatman upon finding one of these bugs, since I was not familiar with the existence of Backswimmers. 

But now I know, and I would have really wondered how a waterbug got on my 2nd story deck, except you explained they can fly well.  The 7/22/10 pic of a Backswimmer swimming (on its back, of course) highlighting the abdominal hairs is especially nice.

I did not bother to submit all the pics I took because I found the ID, as you already have several pictures, including one from 2005. I only attached one for reference.  Later, the Backswimmer had flown away.  Thanks again for such a great site.
Cheers, Dee Warnock


Hi Dee,
Thanks for bringing this to our attention.  We did not realize that Baffled in Santa Cruz submitted the exact same image as Jason, and that Baffled in Santa Cruz had taken the original photo from our site. 

We have included your letter as an update on the Backswimmer that was misidentified as a Water Boatman as well as making it a unique posting since we are certain of the authorship of your photograph. 

Since the postings with the same images came in several months apart, we didn’t realize that Baffled had sent in Jason’s photo.  Because we want to maintain some sense of honesty and integrity to our postings, we have recently added this statement to our form: 

“Also, you swear that you either took the photo(s) yourself or have explicit permission from the photographer or copyright holder to use the image.”  We really like the common name of Water Wasp given to Backswimmers since their stabbing bite is quite painful.

Letter 7 – Backswimmer

Subject:  Interesting bug
Geographic location of the bug:  New Windsor, New York
Date: 11/03/2017
Time: 02:46 PM EDT
I was standing outside of my car this after noon, Nov 3, 2017, and this odd looking insect landed on the roof of my car.  It looked like a class of beetle, but other than that I’m not sure. 

It looked like it could use it’s rear legs to sense the environment around it as it had very fine hairs, almost painbrush like in appearence as it waved them around. 

I manged to get some pictures of it, and I hope they help to identify this unique insect.  I have never seen anything like it and I would love to know more.
How you want your letter signed:  Respectfully, Jesse Trusceo


Dear Jesse,
This is a Backswimmer, an aquatic predator that is also capable of flight.  According to BugGuide:  “hind legs modified for swimming, with long hairs.”  Though they are somewhat clumsy on land, they are adroit swimmers.



  • Bugman

    Bugman aka Daniel Marlos has been identifying bugs since 1999. is his passion project and it has helped millions of readers identify the bug that has been bugging them for over two decades. You can reach out to him through our Contact Page.

  • Piyushi Dhir

    Piyushi is a nature lover, blogger and traveler at heart. She lives in beautiful Canada with her family. Piyushi is an animal lover and loves to write about all creatures.

4 thoughts on “Backswimmer Bite: Is it Poisonous? – Clearing the Myth”

  1. I recently got bit by this exact bug, the backswimmer. Any info on bites? Do they go away? Are they harmful? My bite is larger than a quarter and not diminishing in size whatsoever. Very itchy. Thanks!

  2. Notonectids and many other aquatic bug and beetle families will land on cars. The shiny surfaces probably make the critter think it’s actually water. Your specimen is Notonecta irrorata. You can tell by the irrorate pattern on the hemielytra and the dark splotch on the pronotum.

    • Thank you so much for providing this wonderful information. The shiny surface of a car does resemble the surface of a pond. Thankfully this mistake on the part of the insect does not have the same dire consequences as when a bird flies into a reflective window. Additionally, we had to research the meaning of “irrorate” which is a zoological term meaning “like sand” or “speckled with color” and we will have to make sure we use the vocabulary term today in our daily life.


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