Mud Daubers (or Dirt Daubers) are a type of wasp that have extended tails. They gather dirt and mix it with their saliva to create rock hard nests on the side of homes. These nests (which can be shaped like tubes or blobs of dirt) are hard to remove and leave a permanent stain. Mud Daubers prefer to prey on Black Widows and other spiders. They are normally black with markings of yellow on the body. They have a distinct stretched out body segment located between the thorax and abdomen. Their nests are made of mud hence the name. Prey such as cellar spiders are stung, paralyzed and placed in the clay like nest so that as the larvae hatches, they will have food to feed on. This activity increases before the winter so their larva will survive the cold months. These insects do leave behind pheromones in order to mark their territory. It will cause cosmetic damage once the mud nest has been scraped off the structure. Mud Daubers may be an indication of spiders, especially black widows.