There are about 280 species of Nomad Bees in North America. They are evolutionarily unique because they do not collect pollen to feed their offspring. Instead, they steal it. They are known as kleptoparasites. They enter the nest of a host species of bee and lay eggs. Their emerging larvae will then eat (steal) the resources that the host has already collected. Nomada species exhibit an unusual behavior where adult bees can be found sleeping on a plant using only their mandibles to hang on.
Photo by: Kelly Dix near the Selway River in Idaho