Tom Turpin
Professor of
Purdue University







Insect Masons Build Little Mud Houses

About this time of year, many people notice that their homes are being adorned with mud. Not the proverbial mud tossed around by politicians, but mud brought in by a group of wasps known appropriately as mud daubers.

These insects get their names because they construct mud homes for their offspring. They place their mud structures in protected places. Bridges, abandoned buildings, barns, garages or porches and eaves of human dwellings are prime real estate for these insect mud masons.

Mud daubers acquire the raw material for their nest at the ground level. They frequently can be found crawling around a mud hole picking up soil in their jaws. Once they have acquired a load of the raw material, a ball of wet soil, they fly to the job site. There the soil, mixed with insect saliva, is used to fashion the nest.

Like humans, the mud daubers build their homes in different shapes. The organ-pipe mud dauber produces a series of side-by-side tubes that look like the pipes of a musical organ. Each pipe is fashioned of strips of mud that just happen to be the width of the wasp's jaws. The color of the nest sometimes changes as the pipe gets longer. This reflects the color of the soil used, and the wasp may change the site of soil collection as the nest grows.

Other mud daubers take time to smooth the surface of the nest. In this case, the ridges of soil evident in the organ-pipe mud dauber nest are not evident. The smoothing activity is similar to producing a stucco human home where the masonry material is smoothed over the outer surface.

A few mud daubers really live up to their name. They appear to just deposit the jawsful of mud in a haphazard way on a pile. The resultant home looks like a handful of mud thrown against a wall.

These mud homes have a cavity inside that is filled with food for the immature wasps. This food is often spiders. So once a mud dauber has a room constructed of sufficient size, the room is filled with enough spiders to feed the offspring during their immature life. An egg is then placed in the cell, as the room is called, and the mother then seals the cell with a partition of mud.

Mud daubers are generally black wasps with orange markings or bluish-black in color. As a general rule, these wasps crawl around in a nervous fashion as they work. They move fast and flip their wings and abdomen frequently. Unlike the paper wasps, they almost never sting humans.

Another characteristic of mud daubers is that they sing while they work. When they're working inside a nest under construction, you can hear them making a buzzing sound. To some people that buzzing sound is a happy sound. The sound of a mud dauber building a house for her children — children she will never see because when they emerge next June, she will be gone. But she did what every good mother does for her children — provided a good home and lots of food!


Writer: Tom Turpin
Editor: Andrea McCann