Halictids are also known as sweat bees because a few species are attracted to the sweat. The bees of this family are very variable in appearance, both size and colour. They may be dull-coloured or metallic green, blue or violet (like the tribe Augochlorini of the subfamily Halictinae). Within the family the species present a wide array of behaviours. There are solitary, communal or eusocial bees. There are also parasitic ones. Most of the species are polylectic, that is, they gather pollen from different plant families. So, they are important pollinators. The adults feed on nectar and collect pollen and nectar to feed the larvae. Most species build their nests underground in bare soil. A few, in rotting wood.