Mud daubers are solitary wasps belonging to several species, including Sceliphron caementarium, Chalybion californicum, and Trypoxylon politum. They are recognized by their long, slender bodies, narrow waists, and black or metallic blue coloration, sometimes with yellow markings. Adults measure ¾–1 inch and build distinctive tube-like mud nests on walls, eaves, and in sheltered structures. Female mud daubers provision each nest cell with paralyzed spiders for their larvae to feed on, then seal the cell with mud. They are non-aggressive and rarely sting, making them beneficial for natural spider control. Most species have 1–2 generations annually, with activity peaking in warm months. While they can be a nuisance when nests are built on buildings, they do not damage structures and are generally considered helpful in controlling other pests.