Ground-nesting bees

6962.      These look like tiny bees. They swarm by the 1000’s over my lawn, in cedar shrubs, and higher into lower branches of my beech trees. …from May to July. Looks like they hatch from the soil?? – mainly on sunny days. They appeared about 3 years ago and seem to be getting worse each year. They are only about 1/2″ – 5/8″ long. Wings are folded over the back when resting, unlike in the photo ( this one is dead). Any idea what they are, and should I be concerned? Thanks. Bancroft, Ontario. Canada

Number 6962. This is one of the many species of solitary ground-nesting bees, likely in the subfamily Halictinae. These are valuable pollinators, but some species in this subfamily known as sweat bees will sting if swatted when they alight on your skin (they are attracted to perspiration).