Black Mud Dauber. Mud dauber nests may be considered a nuisance because they are often built on urban structures. The alarming yellow and black coloration on the black and yellow mud dauber causes many observers to slowly back away.

The black and yellow mud dauber (sceliphron caementarium) constructs nest cells side by side or on top of one another;

I have a black mud dauber that nests in the siding of my house by my back door. Adults are commonly seen in wet spots, in preparation of creating the balls of mud for building their nests. While this wasp is certainly capable of stinging, it is not immediately interested in attacking people like other wasps. Sceliphron caementarium, the black and yellow mud dauber.