Do Mason Wasps Sting? Truth Revealed

Mason wasps look similar to many other stinging wasps and are pretty big in size. But do they actually sting humans? Let us find out.

Most mason wasps do not sting, but there is a chance that they may bite you if provoked or disturbed.

They are actually beneficial insects that prey on caterpillars and help remove them from your garden.

However, these wasps may bring other kinds of damage apart from unpredictable stings. Continue reading to learn more about these insects.

Do Mason Wasps Sting

What Are Mason Wasps?

Mason wasps come from the Eumeninae subfamily of the Vespidae family, which also comprises potter wasps.

Mason wasps are usually black-colored with little to no hair. Like many other species, females are bigger than males because they have to carry eggs.

What Do They Look Like?

Mason wasps usually have black bodies. The male is ½ (or slightly over) inches long, while the female is somewhere between ½ to ¾ inches.

Mason wasps, like other wasps, have no or little hair.

A four-toothed wasp of this variety has a visible white band on the upper part of the abdomen and a spot on its face.

These wasps are often confused with others in the wasp family, so let’s point out some differences.

Red and black wasps have black with reddish markings on their body instead of white ones.

The bald-faced hornet wasp is also black but has white stripes at the end of the abdomen instead of a white spot.

Where Are They Found?

Mason wasps are typically found in South America, but many can also be spotted in the Southern US (especially in warmer climates like Florida). Potter wasps, on the other hand, are pretty common across the nation.

Do They Sting?

Mason wasps are stinging insects, and so are potter wasps. Even though these insects sting, they rarely do it to humans unless provoked or threatened.

However, you must avoid their wasp stings since they are painful and can cause swelling, redness, or rashes.

Are They Venomous?

Yes, they are venomous, but they use the venom for hunting caterpillars for their larvae. They attack and paralyze their prey using their poisonous stings and then carry them to the nest to store them as food. Their venom is never directed toward humans or pets.

Are They Aggressive?

Mason wasps are solitary wasps, so they don’t have a nesting colony to defend. Thus, they are usually benign and cannot be considered aggressive like paper wasps.

Their stings, however, are painful, and it’s best to avoid them because the pain lasts for a while. If you are prone to allergic reactions caused by insect bites, you must seek medical help if you get a wasp sting.

Even though mason wasps are not aggressive in nature, they often get confused with wasps like yellow jackets and bald-faced hornets.

These wasps attack aggressively and in groups, especially if they feel their nest is in danger.

Four Toothed Mason Wasp

Where Do They Nest?

Mason wasps usually build their nests in the cracks or holes in wood or abandoned beetle nests.

Mason wasps also dig into mortar, and when in large numbers, they build a nest between bricks also.

The damage caused can lead to the weakening of the wall structure. It can cost you thousands of dollars to rebuild the nested area.

Some mason wasps also build nests in the ground, while others reuse mud dauber wasp nests. As you can see, there are several places where these wasps can build nests, but commonly, they are found emerging out of cracked holes in wood or bricks.

What Do They Feed On?

The adult mason wasp feeds on nectar, but you can see the majority of them attacking and hunting hairless caterpillars, such as cutworms and corn earworms.

If you are wondering why: they hunt and paralyze caterpillars to carry them to their nests. They store these poor insects in one of the chambers of their nests to be used as food for their larvae.

Mason Wasp

Frequently Asked Questions

How do you get rid of mason wasps?

Mason wasps usually take up homes inside cracks or holes in wood. The easiest way to get rid of them is to close up all the holes with PU or putty. It will remove the possible nesting sites of these wasps.
If you are worried about these wasps in the wild, don’t be. They rarely ever attack or sting humans unless you go ahead and provoke them intentionally.

Are four-toothed mason wasps aggressive?

Four-toothed mason wasp species are mild-tempered unless provoked or disturbed.
The female four-toothed mason wasps don’t even defend their nests but can attack if they are mishandled.
These bugs are solitary in nature, they don’t have a colony to defend, so they are not aggressive like yellow jackets.

Where do mason wasps live?

Most of these wasps are found in South America, but a considerable population of these insects can also reside in southern parts of the country, specifically in Florida.
They commonly build nests in the mortar between bricks, cracks in the wood, abandoned beetle nests, and some of them make underground nests also.

Why is it called a mason wasp?

The insect is called a mason wasp due to its pot-shaped mud nest. They use mud or sand as partitions between their larvae rearings or brood cells, which look like little mud pots.
Some of these wasp species also build nests under the ground.

Wrap Up

We hope you know by now that mason wasps do not like to sting humans, and you should not be afraid of them.

So, the next time you see a mason wasp working on its nest, it would be a good idea to leave the insect undisturbed.

Thank you for reading!

Reader Emails

Due to their fascinating habit of making homes in wood, mason wasps are very easily a nuisance for most households.

Several of our readers have asked us about these wasps and whether they are dangerous to remove from the area near their gardens or yards. Please visit some of these letters below

Reader Emails


Letter 1 – Mason Wasp


Hi ,
I love your site & found this guy in my garden ( central Florida ) today. It looks like a bald face wasp but the colors are not right, as it has a black face and a spot of white on each shoulder & a single stripe around the abdomen ? It is a 1"-1.5" long
Thoughts? I would really like to let him go soon but want to know what he is first & if someone in the area would like it/need it for research ? I figure its been found before but I cant find any pictures of it anywhere. Also looks like the wings are blue and have a thin set underneath/over the main set ? Also found this fly LOL in the same catch, the wasp isnt interested in it but likes to pinch it now and then. Also the wasp has large pincers that seem very strong as he is trying to eat at the base of the container I put him in ? Thanks

Hi Chris,
This is a Mason Wasp, Monobia quadridens. You should release this solitary species.

Letter 2 – Mason Wasp


Bee, wasp, fly? Dear Bugman, I spied this creature while out on a walk today. I wonder if it is a bee, wasp, or fly? Susan S. Rockwell Alva, FL (SW Florida) Hi Susan, We thought this might be a Paper Wasp, but Eric Eaton provided us with this information: “Daniel: The “paper wasp” from Alva, Florida is actually a mason wasp, almost certainly in the genus Euodynerus. Eric “

Letter 3 – Mason Wasp


Wasp with purplish wings??????? Fri, Jun 19, 2009 at 10:35 AM Please help me identify this creature that is eating my deck thank you Windsor Ontario Canada
Mason Wasp
Mason Wasp
This is a Mason Wasp, Monobia quadridens.  According to BugGuide it:  “Usually nests in wood borings, but sometimes burrows in dirt banks. Sometimes takes over abandoned nests of carpenter bees or ground bees, also Sceliphron (mud dauber) cells. Nest is provisioned with caterpillars, and cells of nest are separated by mud partitions.”  We do not believe this Mason Wasp is damaging your deck, and you do not neet to fear that it will “eat” it to the point that it is structurally compromised.  The advantage of the caterpillars from your garden that will be used to feed its young far outweighs any damage done to the deck.

Letter 4 – Unseasonably Late Bug of the Month November 2011: Mason Wasp


Mystery (to me) hornet Location: Deep southern Illinois October 31, 2011 3:12 pm While hiking the other day I found this ”hornet” alone and chilly early one sunny day. Can you let me know what kind of bug this chilly fellow is? Signature: JimmyDean
Potter Wasp
Dear JimmyDean, This is a Potter or Mason Wasp in the subfamily Eumeninae, though we are uncertain if Potter Wasp and Mason Wasp are synonymous or if they are two distinct groups within the family.  We believe we identified your Potter Wasp or Mason Wasp as Pseudodynerus quadrisectus, based on photos posted to BugGuide which states it “Nests in borings made in wood, preys on caterpillars” and that it is found from “June-September (North Carolina)”.  Your individual was sighted significantly late in the season.  Perhaps a change in weather patterns is responsible. Editor’s Note:  If you have a late Potter Wasp or other insect sighting, please submit it.

Letter 5 – Mason Wasp from Australia


Subject: Wasps Location: Belair, South Australia November 9, 2012 11:50 pm Hi, I photographed a wasp (?) yesterday and I can’t ID it. I’ve looked through my field guides, and on the Internet endlessly, and I just can’t find an image anywhere. It has been suggested it may be a potter wasp, or maybe even a wasp mimicking bee. Any help would be greatly appreciated. I think it might be an Australian native insect – at least I hope it is. Thanks so much.It’s quite small, maybe 80 mm nose to toe, and the same across wing tip to wing tip. Signature: Paladian46
Mason Wasp
Dear Paladian46, The closest match we were able to locate for your wasp is the Brown Mason Wasp, possibly from the genus Euodynerus that is posted on the Brisbane Insect website.

Letter 6 – Four Toothed Mason Wasp


Subject: Unidentified wasp? Location: Southeastern Ohio December 27, 2012 10:28 am This pollinator appeared for only a few days, feeding on the sedum in my garden in southeastern Ohio. Have not been able to find a photo of this particular critter. Maybe not a wasp? Signature: Toni Leland
Four Toothed Mason Wasp
Dear Toni, Since we just learned that nearly a foot of snow has been dumped on eastern Ohio, we suspect this is not a real recent photo.  If possible, can you let us know which month the sighting occurred?  This is a Four Toothed Mason Wasp, Monobia quardidens, and according to BugGuide it is “Usually seen in open habitats with flowers” just as your email and photo indicates.  BugGuide also notes it:  “Usually nests in wood borings, but sometimes burrows in dirt banks. Sometimes takes over abandoned nests of carpenter bees or ground bees, also Sceliphron (mud dauber) cells. Nest is provisioned with caterpillars, and cells of nest are separated by mud partitions.”  Daniel, I am no longer in Ohio, thank goodness! Yes, lots of snow, and yes, this photo was taken in September of 2010. Thanks very much for the ID. I do a lot of work with gardening sites and need to be as detailed as possible with my photos. Regards, Toni Leland

Reader Emails

Over the years, our website, has received hundreds of letters and some interesting images asking us about these insects. Scroll down to have a look at some of them.

Letter 1 – Mating Mason Wasps


hornets mating Hello, Saw these two mating, the one lying on its back was on top but by the time I got my camera it was in its death throes. Are these Bald Faced Hornets? Nancy Richlandtown , PA Springfield Township (Upper Bucks County) Hi Nancy, Your mating wasps are Mason Wasps, Monobia quadridens. They are nonaggressive solitary wasps. According to BugGuide: “Usually nests in wood borings, but sometimes burrows in dirt banks. Sometimes takes over abandoned nests of carpenter bees or ground bees, also Sceliphron (mud dauber) cells. Nest is provisioned with caterpillars, and cells of nest are separated by mud partitions. “


  • Daniel Marlos

    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.

9 thoughts on “Do Mason Wasps Sting? Truth Revealed”

  1. Just photographed one just south of Ft. Worth, Tx.
    It was not aggressive as I snapped a close up with my phone. Thought it was a mud dauber, as they have all begun to fly in the last two weeks!!!

  2. Just saw one. It was here last year too. Cambridge, Ontario, Canada. It is investigating the carpenter bee nests.
    Last year, a big black wasp (I think it was a four toothed mason wasp) flew in carrying a huge larvae and placed it in the carpenter bee nest.

  3. I saw the same thing yesterday in my backyard and I am from Melbourne! I’m very curious as to what it is?

    Unfortunately the one in my backyard died 🙁


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