To find sweat bees in the garden, choose a patch of flowers and watch one blossom closely. The small visitor turning among the stamens may be easy to miss. Look for pollen on her hind legs and watch where she goes when she takes off.
How to spot sweat bees in the garden
Sweat bees belong to a large family called Halictidae. Some are metallic green. Others look dark, with pale bands across the abdomen. A green flash can draw your eye, but color alone rarely identifies the species. A photograph from the side can show features that disappear when you look straight down.
Look for two different jobs on the same flower. A bee that drinks nectar takes in fuel for flight. A female that gathers pollen can carry it back to feed her young. While the bee gathers food, some pollen can brush off onto the next flower of the same kind. That transfer helps many plants make seeds. You can see a visit happen in seconds, although the seeds themselves develop later.
Why does a sweat bee land on people?
If sweat bees in the garden land on your arm, they may be seeking salt from your perspiration. Hold still and give the bee room to fly back to the flowers. Children can watch a bee on a blossom without trying to hold it. Illinois Extension describes sweat bees and other common native bees.
Where sweat bees in the garden make their nests
Look at the ground, too. Many sweat bees tunnel into soil. Green sweat bees in the genus Agapostemon, for example, nest underground. In some species a female works alone. In others, several females share an entrance. Watch from the path and leave any opening clear.
If you garden, leave a small patch of well-drained soil undisturbed where you have seen bees coming and going. For close-up identification details, see the University of Minnesota guide to green sweat bees.
Count visits from sweat bees in the garden
When you count sweat bees in the garden, pick two flowers of the same kind. For five minutes, tally the visits to each. A bee that comes back counts as another visit, so record visits separately from the number of individual bees you can recognize. Sketch one visitor, note the weather and repeat the count another day. What changed?
Find more bee activities for families and classrooms to use on your next garden walk.