Applied to a number of wasps that build their nests out of mud, mud dauber wasps are also referred to as dirt daubers, dirt dobbers and dirt divers. Beneficial in insect and spider control, mud daubers consist of two families, Sphecidae or Crabronidae, and while different species vary in appearance, mud daubers are generally 1 inch in length and sport long, slender bodies with threaded waists.
Solitary wasps, mud daubers do not form social colonies. Raising two generations annually, female mud daubers build their mud nests, attaching them to different surfaces depending on the type of mud dauber:
- Organ pipe mud daubers
In the Crabronidae family, organ pipe mud daubers build elegant nests of connecting cylindrical tubes resembling the pipes or flutes of a pipe organ. Female organ pipe daubers build these unusual and striking nests on walls, bridges, cliffs and caves on vertical, as well as horizontal faces.
- Black and yellow mud daubers
In the Sphecidae family, black and yellow mud daubers construct nests of cylindrical tubes and then smooth the tubes over to make one, round shaped nest. Because they lay one egg per nest, black and yellow mud daubers usually build several nests and plaster over the units to form one larger, urn-shaped nest attached to corners, crevices or cracks in buildings.
- Metallic-blue mud daubers
In the Sphecidae family, metallic-blue wasps utilize abandoned nests of other mud daubers, especially black and yellow mud dauber nests. Repurposing and reconditioning nests by applying water to the nests, blue mud daubers gather food for their young that includes black and brown widow spiders. Both black and yellow and metallic blue mud daubers frequently occupy the same nest site areas, such as porches and barns.