Nomada are conspicuous, wasp-like parasitic bees of variable size. They have a slender, relatively hairless body and are usually covered with colorful patterns combining different shades of yellow, red, black and/or white. Males and females may look alike, but often have different eye color. Females usually have orange-brown or deep red eyes while the eyes of the males are either pale green or greyish blue. Identification to species level can be complicated and often requires visible male genitalia. They are cuckoo bees that are active mainly in spring and attack the burrows of ground nesting bees, such as Andrena, Lasioglossum, Melitta and Eucera. Females may be seen patrolling aggregations of their host species, searching for open nests to deposit their eggs in unattended food provisions. Upon hatching, the larvae kill the brood of the host to consume the food.