Mud daubers: are they dangerous, and why are they here?
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By John Stopka, Co-Founder & CEO · Reviewed by John Stopka
Mud daubers are solitary wasps that build nests out of mud and stock them with spiders for their young. They are long and slender, with a thread-thin waist, and they rarely sting: each female works alone, so there is no colony and no nest to defend. The mud tubes on a porch ceiling or garage wall are the part people notice, and they are usually the only problem.
What is a mud dauber?
A mud dauber — a dirt dauber across much of the South — is a wasp that builds with mud instead of paper. University of Kentucky entomologists group them with the narrow-waisted solitary wasps, which attach their mud nests to rocks and buildings [1].
Unlike paper wasps, hornets and yellow jackets, mud daubers don't live in colonies. Each female builds and stocks her own nest.
What do the common mud daubers look like?
Three are common around homes here, and the nest is the easiest way to tell them apart [2]:
- Organ-pipe mud daubers are black, and build tubes side by side that "can be a foot long and resemble the pipes of a pipe organ" [2].
- Black-and-yellow mud daubers are brownish-black with yellow markings; their nests are about 2 inches long [2].
- Blue mud daubers are shiny, metallic blue and black, with blue wings [2]. They often move into old nests other mud daubers have left.
Are mud daubers dangerous? Do they sting?
They can sting, but they rarely do. Clemson Extension describes mud daubers as solitary and non-aggressive, stinging rarely unless they are threatened [3].
A sting usually happens when one is grabbed or pressed against skin. Anyone concerned about a reaction to a sting should contact a healthcare provider.
Why are mud daubers around my house?
Spiders and shelter. Mud daubers stock their mud cells with spiders, which the female stings and paralyzes as food for her larvae [1][2]. A house with plenty of spiders around it is a good hunting ground.
They build where the mud stays dry: under eaves, on porch ceilings, in garages and sheds, and on the undersides of anything left outside. Clemson adds cracks, crevices and openings in equipment [3]. Fewer spiders and fewer sheltered gaps mean fewer mud daubers [3].
Is an old mud dauber nest still active?
Look for small round holes. A nest with holes in it is empty: the young wasps have already chewed their way out.
Old nests are mostly a nuisance. They stain siding and collect in the same sheltered spots year after year.
Mud dauber nest or termite tube?
Both are mud, and the difference matters. Mud dauber nests sit on walls and ceilings, often as gray tubes side by side or a lumpy mass of mud cells. Termite tubes are pencil-wide and run up from the soil along foundation walls and floor joists, which is where signs of termites start. A mud tube that climbs a foundation from the ground is worth a termite inspection, not a scraper.
How does Liberty handle mud daubers?
Mud daubers are wasps, and wasps are a plan pest, handled on regular pest control visits. Plans cover wasps on the first floor of your home. They scrape mud dauber tubes off walls and ceilings on the first floor.
When to call a professional
Call when nests are above the first floor, inside a vent or somewhere you can't reach safely, when they keep coming back to the same spots, or when you can't tell whether a mud tube is a mud dauber's or a termite's.
Common questions
Are mud daubers dangerous?
Rarely. They can sting, but they don't live in colonies and don't defend their nests the way yellow jackets do [3].
Do mud daubers sting?
They can, but usually only when one is grabbed or pressed against skin [3].
Is a dirt dauber the same as a mud dauber?
Yes. "Dirt dauber" is the name used across much of the South.
What do mud daubers eat?
The adults hunt spiders, but not to eat them: they paralyze them and pack them into the mud cells as food for their young [1][2].
Are mud daubers covered by my plan?
Yes. Mud daubers are wasps, and plans cover wasps on the first floor of your home.
Sources
- University of Kentucky Entomology. "Narrow-Waisted Solitary Wasps of Kentucky" (Critter Files). https://www.uky.edu/Ag/CritterFiles/casefile/insects/wasps/solitary/solitary.htm (opens in a new tab)
- University of Illinois. School IPM. "Mud Daubers". https://schoolipm.illinois.edu/muddaubers/ (opens in a new tab)
- Clemson Cooperative Extension, Home & Garden Information Center. "Mud Daubers: Identification, Habits, and Control". https://hgic.clemson.edu/factsheet/mud-daubers-identification-habits-and-control/ (opens in a new tab)