Mud dauber

Mud dauber (or 'mud wasp' or 'dirt dauber') is a name commonly applied to a number of wasps from either the family Sphecidae or Crabronidae that build their nests from mud. Mud daubers belong to different families and are variable in appearance. Most resemble long, slender wasps about 1 inch (25 mm) in length. The name refers to the nests that are made by the female wasps, which consist of mud molded into place by the wasp's mandibles. Mud daubers are not normally aggressive, but can become belligerent when threatened. Stings are uncommon. The organ pipe mud dauber, one of many mud daubers in the family Crabronidae, builds nests in the shape of a cylindrical tube resembling an organ pipe or pan flute. Common sites include vertical or horizontal faces of walls, cliffs, bridges, overhangs and shelter caves or other structures. The nest of the black and yellow mud dauber is a simple, one-cell, urn-shaped nest that is attached to crevices, cracks and corners. Each nest contains one egg. Usually several nests are clumped together and covered in mud. The metallic-blue mud dauber, another sphecid, builds mud nests, but occasionally refurbishes the abandoned nests of other species; it preys primarily on spiders. The two species commonly occupy the same barns, porches, or other nest sites.