Lasioglossum is a genus of sweat bees. They're called sweat bees after their weird attraction to the smell of human sweat!
Lasioglossum holds over a whopping 1700 known species around the world, making it the largest bee genus.
Many species are solitary or communal. Solitary means that the female will care for young alone; communal meaning 2 or 3 female bees will share the nesting site and care for young together. Some are parasitic, stealing the nests of other bees.
Most are ground-nesting, but some will nest in things like deadwood and tree branches.
Most are generalist pollinators, pollinating a variety of crops and wildflowers. Others share special relationships with plants, visiting only a few species or genera for pollen and nectar.
Because of their small size, they're seldom noticed by gardeners or those passing by. Often, they're mistaken for flies!
There's approximately 30 known species in the UK.