Black-and-yellow mud daubers build a simple, one-cell, urn-shaped nest that is attached to crevices, cracks and corners.

Blue mud daubers frequently appropriate old nests of black-and-yellow mud daubers.

Like most other wasps, mud daubers are predators.

Missouri's mud daubers generally have two generations per year.

Brown widows are often preyed on by mud daubers and sometimes by digger wasps.

Juveniles are frequently preyed upon by mud daubers.

The difference between normal wasps and mud daubers can be seen easily because of its long petiole.

Like other mud daubers, it is rarely aggressive.

But it does keep the mud daubers from building their little nests.

Everyone comments as they drive by, "Noticed you painted your ceiling blue; trying to keep the mud daubers off?"