There are many species of sweat bees, or halictids, in several genera in Missouri. All are small; none are aggressive. Most members of this family are black or brown, but some are brightly colored, notably with metallic greens and blues. Their markings vary from green to red to yellow, often with bands similar to those of honeybees. All have short tongues, compared to other types of bees.

Specialists note details of wing venation, antennae structure, and other characteristics to distinguish this group from other bees, and to distinguish the various sweat bees from each other.

One of the most noticeable traits of sweat bees is their attraction to perspiration, which offers them precious moisture and salts.

Similar species: Cuckoo wasps (in family Chrysididae) are also small bee- or wasp-type insects in metallic blues and greens, but their bodies are usually covered with small pits, giving them a sculptured or pebbly look. Also, they can roll up into a ball for defense. Female cuckoo wasps cannot sting, which might explain the protective defensive posture in that group.

Several other types of bees and wasps are metallic-bodied, too.