The Black and Yellow Mud Dauber: Nature’s Crafty Architect

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The Black and Yellow Mud Dauber is a species of solitary wasp scientifically known as Sceliphron caementarium.

Commonly found across various regions, these wasps are known for their distinct appearance and unique mud nests.

Known to be non-aggressive, they are dark with metallic hues and thin waists, often spotted hunting spiders to feed their offspring.

Black and Yellow Mud Dauber
Black and Yellow Mud Dauber

Female Mud Daubers create their nests from mud, each cell containing a single egg.

To provision their offspring, these protective mothers collect up to 25 live, paralyzed spiders per cell.

Despite their slightly intimidating appearance, these wasps rarely sting unless threatened, rating just a 1 on the pain scale which ranges from 1 (mild) to 4 (severe).

Black and Yellow Mud Dauber Overview

Species Description

The Black and Yellow Mud Dauber (Sceliphron caementarium) is a member of the wasp family, Sphecidae, within the order Hymenoptera.

They are solitary wasps known for their unique mud nests and hunting of spiders.

Color and Size

The black and yellow mud dauber gets its name from its distinct coloration, featuring a combination of black and yellow patterns on their body.

They have a long, slender waist and a size of about 1 inch in length.

Example of related species:

  • Organ pipe mud daubers (Tropoxylon clavatum and T. politum)
  • Blue mud dauber (Chalybion californicum)

Comparison table:

Black and Yellow Mud DauberBlack and yellow~1 inch
Organ Pipe Mud DaubersMetallic black/blueSimilar
Blue Mud DauberMetallic blueSlightly smaller

Habitat and Distribution

Geographical Range

The black and yellow mud dauber (Sceliphron caementarium) is native to North America and can be found across a wide range of regions.

Black and Yellow Mud Dauber preys on Orbweaver

Its range stretches from Canada to the United States, Central America, and the West Indies.

The species has also been accidentally introduced to Europe and Australia.

North AmericaNative
United StatesNative
Central AmericaNative
West IndiesNative

Common Habitats

Black and yellow mud daubers can be found in various habitats, such as:

  • Meadows: BYMDs are often seen in open meadows where they have easy access to mud and spiders, their primary food source.
  • Gardens: They can also be found in gardens where the abundance of insects and spiders provides a steady food supply.

These wasps are known for building their nests from mud in different types of locations, including:

  • Walls and ceilings of buildings: They often use sheltered areas where their nests can remain safe from weather elements.
  • Vegetation: Some nests are built in vegetation or abandoned cavities, providing them with a more natural habitat.

Overall, the black and yellow mud dauber is a widely distributed wasp that adapts to various habitats within its geographical range.

Life Cycle and Behavior

Nesting Habits

Black and yellow mud daubers (Sceliphron caementarium) are known for their unique nesting habits.

They construct their nests using mud, which are often found in sheltered areas such as under rock ledges, on vegetation, or even on man-made structures.

These nests can take different forms, such as globular or organ pipe-shaped.

  • Globular nests: built by the black and yellow mud dauber, containing one cell per nest
  • Organ pipe nests: built by the organ pipe mud dauber (Trypoxylon)

Reproduction and Development

The life cycle of the mud dauber begins when a female lays a single egg in each cell of her nest.

She then provisions the cell with paralyzed spiders, which serve as food for her developing larva.

In spring, the larva hatches from the egg and feeds on the spiders. As it grows, it will eventually pupate and develop into an adult mud dauber.

Feeding Habits

Mud daubers have a diverse diet, targeting a variety of spiders as prey. Some common spiders they prey on include:

  • Crab spiders
  • Widow spiders, including black widows
  • Orb weavers

In addition to spiders, adult mud daubers also feed on nectar and honeydew, a sweet substance produced by aphids, to sustain themselves.

This sets them apart from other wasp species like paper wasps, which typically do not consume nectar.

Human Interaction and Other Interesting Facts

Effects on Human Environments

Black and Yellow Mud Daubers often build mud nests in various human structures, such as eaves, garages, attics, and barns.

They are not typically aggressive towards humans. Yet, their stings can be painful and can cause discomfort, with their venom primarily meant for paralyzing prey1.

Their presence can also be beneficial, as they control spider populations by paralyzing them and feeding them to their larvae2.

Black and Yellow Mud Dauber

Fascinating Trivia

Here are some interesting facts about Black and Yellow Mud Daubers:

  • Their thin legs and elongated body are designed for capturing their prey, mainly spiders2.
  • They have large eyes that help them locate and identify their prey efficiently.
  • Related species include the Chalybion californicum (blue mud dauber) and the Trypoxylon politum3.

Comparison between Mud Daubers and other Wasps:

FeatureMud DaubersOther Wasps
ColorBlack and yellowVarious colors
Nest constructionMud nestsIn vegetation/cavities
PreySpidersOther invertebrates


In conclusion, the Black and Yellow Mud Dauber (Sceliphron caementarium) is a solitary wasp renowned for its distinctive appearance and unique mud nests.

While they might appear intimidating due to their vibrant coloration and hunting habits, they are generally non-aggressive towards humans.

Females meticulously construct their nests from mud, each containing a single egg, and provision them with paralyzed spiders as food for the larvae.

These wasps play a crucial role in the ecosystem, controlling spider populations.

Their presence in human environments, such as buildings and gardens, can be both intriguing and beneficial.


  1. Mud Daubers | Home & Garden Information Center

  2. black and yellow mud dauber – Sceliphron caementarium 2

  3. Mud Daubers | University of Maryland Extension

Reader Emails

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

Letter 1 – Mud Dauber Nest in Australia

Subject: What are these clay light shells
Location: Sydney Australia
January 28, 2017 8:07 pm
Found these in the backyard and just wondering what they were shells of..
Signature: Cindy

Mud Dauber Nest

Dear Cindy,
This is a mud nest constructed by a Wasp, probably a Mud Dauber in the genus
Sceliphron based on the image posted to Oz Animals.  The Brisbane Insect site has images of a female Mud Dauber constructing her nest as well as this information: 

“The wasps build mud cells in sheltered locations. If the cell is opened, you will find a wasp larva, together with some spiders which are the larva’s foods. They are collected by the mother wasp.”

Letter 2 – Mud Dauber Mystery related to mating.

Subject: what is going on with these wasps
Location: near houston
April 28, 2017 9:56 am
very odd. 4 wasps on top of each other. At first ii thought it was a multiple mating, but It appears that the bugs on top are dead.

What is going here? what sort of wasp is this? is this normal? i’ve never seen this before.
Signature: jay in texas

Mud Dauber Mystery

Dear Jay,
We wish you had been able to provide better quality images.  While there is enough detail to determine that these are Black and Yellow Mud Daubers,

Sceliphron caementarium, and it appears they are “attached” to one another at the head like each was biting another at the “neck”, we cannot fathom what is going on or what happened. 

It is interesting that you observed the the ones on top are dead.  Does that mean the ones on the bottom were alive? 

It also appears that they are on a collapsible hose, which makes sense since Mud Daubers are often found near puddles that occur when watering or near swimming pools. 

You may verify our identification by comparing your individuals to this BugGuide image. 

Mud Daubers are solitary Wasps, and each female makes and provisions her own nest, so this “group activity” is quite puzzling.  We will contact Eric Eaton to see if he can provide a hypothesis on what is happening.

Update:  Supposed Mating Behavior
Thanks to Cesar Crash who provided comments with links to Shutterstock and BugGuide.

Eric Eaton Confirms
….Three males competing for a female (bottom-most individual).  The neck-grabbing is typical male mate-guarding behavior, or attempt to mate.
author, Kaufman Field Guide to Insects of North America

Letter 3 – Mud Dauber Nest

Subject: bugs nest
Location: Miami,Florida
July 29, 2015 10:27 am
Please help me figure out what this is.
Signature: Tiffany

Mud Dauber Nest
Mud Dauber Nest

Dear Tiffany,
This is the nest of a Mud Dauber, a solitary wasp that builds a nest of mud that is comprised of numerous cells provisioned with paralyzed spiders.  Each cell contains a single egg. 

By the look of your nest, the adult Mud Daubers have already emerged to forage, pollinate flowers and possibly begin building a new generation of mud nests in sheltered locations, often in the corners of windows and under eaves. 

Mud Daubers are not an aggressive species that can often be found collecting mud in gardens and other areas that are watered.

Letter 4 – Mud Dauber Nest

Subject: What is this nest?
Location: Top of an outdoor window
July 9, 2017 10:34 pm
I live in Scottsdale, AZ and this nest was not here yesterday. What is it and should I leave it alone? I’m vegan so I will only rid it if it is dangerous! Thank you!
Signature: Tina

Mud Dauber Nest

Dear Tina,
This is a Mud Dauber Nest, the nest of a non-aggressive, solitary wasp, probably the Black and Yellow Mud Dauber, that is often found near sprinklers and swimming pools where it gathers mud with which to construct its nest. 

It appears your nest is at the beginning stages of construction.  Eventually, the female Mud Dauber will add additional chambers and each will hold a developing larva and the paralyzed spiders that will provide its food supply.

Letter 5 – Mud Dauber Nest

Sceliphron caementarium in LA County – part 2
Location: E Los Angeles County
September 23, 2011 10:49 am
I sent pictures of the black and yellow mud dauber recently, and then discovered the mud daubed nest – mud huts? – for the larvae – at least I think so since these were on the inside of my garage door and the wasp was captured in my house. Now the connection is clear.

I have never seen this carefully constructed wasp nest before so thought this might be a nice addition for identifying this wasp being in the vicinity. The nest was too high for me to put a comparison measure in the picture, but the tubes are about 1.5-2 inches in length and about 1/3-1/5 inch in diameter.

The tubes are sealed in these pictures. About a week later, the doors were clearly open and tubes empty. When my gardener removed them, he broke open the mud and they were nearly hollow with only one dessimated carcass of a spider at the very end of one tube. Fascinating!
Signature: Fascinated in California

Mud Dauber Nest

Dear Fascinated in California,
Thank you for providing us with the image of the Mud Dauber Nest to accompany your previous posting of the adult wasp.

Letter 6 – Yellow Legged Mud Dauber

Subject:  What’s this wasp
Geographic location of the bug:  Kingston Ontario Canada
Date: 07/06/2021
Time: 08:42 AM EDT
Your letter to the bugman:  Is this a wasp that is helpful?
How you want your letter signed:  Hope Alberry

Yellow Legged Mud Dauber

Dear Hope,
This is a Yellow Legged Mud Dauber or Black and Yellow Mud Dauber,
Sceliphron caementarium, which is pictured on BugGuide.  This is a solitary wasp and solitary wasps rarely pose a stinging threat. 

Social Wasps will often sting to protect the nest, but solitary wasps do not protect the nest.  The Yellow Legged Mud Dauber builds a nest from mud and is often seen near mud puddles.  According to BugGuide:  “nest is provisioned withNests are provisioned with spiders”.

Letter 7 – Mating Mud Daubers

Subject: Mud Dauber Exhibitionists
Location: North Las Vegas NV
June 1, 2017 1:46 pm
It’s the beginning of Summer here in Las Vegas NV and as I was going back into the shop I spotted a small orgy.
Not sure what that top male thinks he’s doing, but I’m sure everyone is having a good time!
Signature: Unintentional Voyeur

Black and Yellow Mud Daubers Mating

Dear Unintentional Voyeur,
Apparently, multiple male Black and Yellow Mud Daubers competing for the same female is not unusual behavior as this image from our archives illustrates.

Letter 8 – Blue Mud Dauber

Subject: Pretty metallic blue insect
Location: Blackwater National Wildlife Refuge, Maryland
May 27, 2017 3:56 pm
Saw this beautiful critter land on a leaf at Blackwater National Wildlife Refuge on Maryland’s eastern shore. Thought at first I had a six-spotted tiger beetle, but the color and the wings seem wrong for that. What do I have here?
Signature: Rob Nease

Steel Blue Cricket Hunter

Dear Rob,
This beauty is a Thread-Waist Wasp in the family Sphecidae that is commonly called a Blue Mud Wasp or Blue Mud Dauber,
Chalybion californicum.  According to BugGuide:  “Females construct mud nests in sheltered areas, often under the eaves of buildings, and provision them with spiders. Sometimes refurbishes the nests of other mud-daubers, such as Sceliphron.”

Letter 9 – Mud Dauber Nest

Subject: Strange “next” on house wall
Location: Garden Grove, California
July 31, 2017 12:23 pm
These “things” are adhering to the stucco on the outside of the house. They are very hardy. No amount of hose spray will bring them down. I have eliminated other things like wasp nests before. Never seeing anything like this.
Signature: Bugged in California

Mud Dauber Nest

Dear Bugged in California,
This looks to us like a Mud Dauber Nest.  Mud Daubers are beneficial wasps that are not aggressive.  There is no need to hose it away.

Letter 10 – Mud Dauber Wasp

Hello, what is this insect? It has one pair of wings, the colors on it are black and yellow. I just thought it was odd that it’s abdomen was so skinny. It tends to fly quite slowly and it whirs whilst it flies. It is a wasp of some sort? Although the patterns of black and yellow are not striped, looks more spotted.

Hi T.
There is a reason “wasp-waist” has been used to describe a femine physique that has a tiny waist and awesome curves. Your Mud-Dauber from the genus Sceliphron also possesses a textbook thread waist. The species does have two pairs of wings.

Letter 11 – Organ Pipe Mud Dauber Nest

Photo of strange tubular insect home
My fiance has recently moved from Michigan to Noth Carolina. It is amazing how many more bugs live in a sub-tropical climate! Anyhow, she is terrified of these nests she has founbd on her new deck. Can you identufy these nests? Is this something she needs to be aware of or something that presents a possible danger? Thanks for the help,
Charles W. Nivison

Hi Charles,
What a very large photo of a very large ceiling with a little Mud Dauber Nest in the center. These are solitary wasps that build nests of mud and fill them with paralyzed spiders, grasshoppers, leafhoppers, flies or other insects that serve as food for the young. Each species of wasp has a very specific food source.

The wasps can sting, but will only do so if provoked, by say, a broom knocking down their nest.
Ed. Note: (09/06/2004) Eric just wrote in identifying the species as the Organ Pipe Mud Dauber, Trypoxylon politum, and informed us they prey on spides only.


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16 Comments. Leave new

  • I don’t write many responses, however i did some searching and wound up here Organ Pipe Mud Dauber Nest – What’s
    That Bug?. And I do have a couple of questions for you
    if it’s allright. Could it be just me or does it give the impression like a few of these responses look as if they are left by brain dead visitors? 😛 And, if you are posting at additional places, I’d like to follow anything fresh you have to post.
    Would you make a list of all of your shared pages like your Facebook page,
    twitter feed, or linkedin profile?

    • What’s That Bug? keeps our limited staff very busy and we don’t have time to post elsewhere. We do not like to judge our readership too harshly. One of the reasons many folks write to us is that they know nothing about insects, but they are curious nonetheless.

  • I don’t write many responses, however i did some searching and wound up here Organ Pipe Mud Dauber Nest – What’s
    That Bug?. And I do have a couple of questions for you
    if it’s allright. Could it be just me or does it give the impression like a few of these responses look as if they are left by brain dead visitors? 😛 And, if you are posting at additional places, I’d like to follow anything fresh you have to post.
    Would you make a list of all of your shared pages like your Facebook page,
    twitter feed, or linkedin profile?

  • Reply
  • Rick Trapp
    May 9, 2017 6:48 am

    I took pictures of something just like this, shortly after I took the pic they all were dead.

  • Hi my name Is Jodie I was just wondering if mud wasps are found in. Asutrailia can you please send me some infomation on them please i have two cats and one of my cats likes to play with insects I think he got stung by one of these

  • It’s not the write information I was after it was on the bluee green wasp

  • I found eight of these gray mud nests inside and on my boat trailer drum brake back plate. There is an extremely small space between the drum and the back plate for the insects to get thru yet they got in and formed a nest and hopefully were able to get out.

  • Witnessed this a few weeks ago in tx. Today, Approached 4 stacked that fell from sky (almost as soon as they hit the ground). All four scattered and flew off, alive. Mating was my first guess, but I didn’t understand exactly what was going on until I found you guys.

  • Like the poster, I never want to cause harm to any living being. My question is about the black and yellow Mud Daubers who come into our Venice Beach home (doors always open), and make nests on the back of pictures hung on our walls? I no longer peek behind the pictures, rather just assume nest(s) are being built when I see the (real focused) female in a room in our house. The question is about the offspring- how many, how small, and their safe exit once born? Once in a great while, we close most our doors at night; will they be led out by Mama the next day?

    • The young will remain in the nest until they emerge as adults, at which time they will likely be found near doors and windows as they try to get outside.

  • I’ve removed these nests from my stucco using a scraper that you would typically use for removing ice from your car windshield. I have been bitten by a wasp on my front lawn with no provocation, so I remove them by first spraying with wasp spray, then scrape with scraping tool.


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