Blue mud dauber
Jeff Hahn, University of Minnesota Extension
Joseph Berger, Bugwood.org
Size: 3/4 - 1 inch long
Description: Black with just a little iridescence.
Where/When: Constructs its nests in cavities in plant stems and in buildings. Carries water to a source of soil near its nest to moisten it so it can use the mud to build its nest; found June through August.
Significance: Not aggressive, stings are rare. Does not harm buildings where they build their nests.