Mud Dauber is a name given to a variety of wasps that build their nests from mud. You may see their nests stuck on the side of a structure, under the eaves, or in an attic. The nature of their nest means that it must be kept dry, so they usually construct it in an out-of-the-way place that can be difficult to access. Mud Daubers look like your typical wasp but tend to be black in color.