Have you seen these weird-looking mud tunnel nests? They belong to the dirt dauber (also known as the mud wasp or mud dauber) belonging to the family Sphecidae or Crabronidae. These different families vary in appearance but most are long, slender wasps about 1 inch in length.
The female wasps makes these cool nests using it’s manibles (a pair of appendages near the insect’s mouth, and the most anterior of the three pairs of oral appendages, which is used to grasp).
The dirt daubers rarely become aggresive and sting. The ones known as the organ pipe dirt or mud daubers build their cylindrical tubes on sites which include vertical or horizontal faces of walls, cliffs, bridges, overhangs and shelter caves or other structures. The yellow and black daubers build one, two or three celled, cigar shaped masses in crevices, cracks and corners. They will contain one egg each. They will usually create several cells and cover them all with mud.
The blue mud dauber can create the mud nests but often just take over abandoned nests. The nests are also used by other kinds of wasps and bees, as well as other types of insects. If a predator finds the nests it is simple to plunder cell by cell.
Like most solitary wasps the daubers paralyse their prey, with their stinger, on which they lay their eggs. Males will guard the nests which is extremely rare for insects. The black and yellow daubers feed on small, colorful spiders, such as crab spiders (and related groups), orb weavers and some jumping spiders.
Blue daubers mostly feed on the black and brown widow spiders. The venom acts as a preservative keeping the prey in proper condition to allow the larvae to develop. An egg is laid in each cell stocked with several prey individuals. When the egg hatches, the larvae feed on the prey. Upon completion of its development, the new wasp will chew a hole in the cell wall and emerge.