Mud Daubers: What to Know

Medically Reviewed by Mahammad Juber, MD on January 23, 2023
5 min read

Bees, wasps, and hornets have found unique ways to survive in habitats all around the world. Mud daubers are a type of wasp that has developed a particularly interesting nesting behavior — they grow their young in individual mounds and tunnel systems that they create out of mud. 

Some people think of mud daubers as pests because they like to build their nests around the edges of buildings. But — overall — they’re not bad creatures to have around. Learn to identify these insects so you know what to do if you find one in your area.

Mud daubers are in the insect order Hymenoptera. This order contains all species of bees, wasps, and hornets and a number of other creatures. For the most part, mud daubers are in the Sphecidae family. This family is made up of solitary wasps.  

People use the common name mud dauber to describe the group of wasps that build structures out of mud. These spaces are used by their young as they grow and develop. Other wasps in the Sphecidae family that don’t build earthen structures tend to create more typical underground hives.  

What do mud daubers look like? Throughout their lifetimes, mud daubers undergo a complete metamorphosis. This means that they transition from eggs to blind, maggot-like larvae. They complete their transition when they take on their winged, adult forms. 

The adult forms also have specialized mouthparts that are used to drink flower nectar. Their bodies come in a wide array of colors including: 

  • Black 
  • Brown
  • Blue 

Most also have some form of yellow or white markings. 

A mud dauber’s exact size depends on the species that it belongs to. Many of them are less than an inch long. Females tend to be slightly larger than males. 

What do mud daubers eat? Adult mud daubers mostly survive off of flower nectar. They actually get most of their nutrients when they’re still in their juvenile stages. 

For the most part, juveniles survive off of spiders that are sealed into their mud homes by their parents. Popular types of spiders in this wasp’s diet include: 

  • Orb weavers
  • Black widow spiders
  • Comb-footed spiders

Adult wasps paralyze the spiders with their stingers and then transport them to the earthen mounds for their young. 

The adults are very efficient spider hunters. There are even reports of mud daubers landing in the webs of orb weavers to trick them into coming out. Then they quickly hit the spider with their stinger and disentangle themselves from the web. 

The growing children can also eat crickets and grasshoppers.

There are a variety of mud daubers throughout the world. Examples of two mud dauber species that are in separate genera are described below.

Sceliphron caementarium. This species is commonly known as the yellow-legged mud dauber wasp. The species name caementarium means “a builder of walls”. These wasps are especially good at constructing earthen homes for their young. They have exceptionally narrow — almost stick-like — thoraxes and yellow and black coloration.  

Chalbion californicum. The common name for this species is the blue mud wasp. They have metallic blue or blue-green bodies. You can find this species anywhere from southern Canada to Northern Mexico. Males can grow up to one-half of an inch in length. Females can grow to be 7/8 of an inch long. Interestingly, this species doesn’t actually make mud nests. Instead, females recycle old nests that were created by members of the Sceliphon genus.

You can find mud daubers in most habitats, including:

  • Deserts
  • Grasslands
  • Forests

They can survive anywhere that they can find spiders, flowers, earth, and a little bit of water.

If you have mud daubers in your area, you may see evidence of their nests around your building’s foundation. Look for any abnormal mounds or formations in the soil. You’ll likely see adult wasps in the area while they try to fill these nests with prey for their young. 

You’re more likely to have mud daubers if you have a thriving insect population in your yard. They’re particularly fond of spiders. So the more spiders that are in your yard, the greater the chances are that you’ll attract some mud daubers. 

Mud daubers aren’t particularly aggressive creatures. For the most part, they’ll only attack and use their stingers if they feel threatened. But even on sting can be fatal for people with bee and wasp allergies. 

The majority of people who just receive one sting will only feel the symptoms of a typical bee or wasp sting. All of the symptoms will occur near the spot where you were stung. These mild symptoms can include:  

  • Pain
  • Swelling
  • Itching 

Unfortunately, people who are allergic to bees and wasps could experience anaphylaxis — a severe allergic reaction — after getting stung. Signs of an allergic reaction include: 

Even if you’re not allergic, you could still develop problematic symptoms if you get stung multiple times. Symptoms that you could experience after multiple stings include: 

Do mud daubers bite? Mud daubers aren’t known for their bites. The most dangerous interaction that you’ll have with a mud dauber is when one stings you.

You need to call 911 or get emergency medical attention if you get stung by a mud dauber and know that you’re allergic to their venom. You should also get immediate medical attention if you experience any concerning symptoms after getting stung. Symptoms that are the most worrying aren’t localized to the spot where you were stung.

People with allergies should also use an allergy response kit if one is available. This can include potentially life-saving products like EpiPens. Just make sure that you know how to use all of the products in your kit before trying them on yourself or someone else.

If you’re only experiencing a mild, normal reaction near the site of your sting, then you should: 

  • Wash the spot with soap and water
  • Apply an antihistamine cream or cortisone cream to help soothe your symptoms
  • Use ice to reduce swelling
  • Take over-the-counter pain relievers to help with any pain

To kill them, you can try directly spraying mud daubers with bee and wasp repellants. If you manage to locate their nests, then you can also find an insecticide that’s safe to inject into your yard and spray it down into the area. 

Just do your research before selecting a repellant or insecticide. These products can be dangerous to humans and pets as well as unintended insects. To maximize your safety, read all of the instructions on the packaging carefully. Then follow them exactly as they’re written. 

Many people don’t mind having mud daubers around because it means a significant reduction in the local spider population. You’ll need to decide what to do about these pests on a case-by-case basis.