A: Andrenidae is the family which contains mining bees. These bees build nests in the ground and they are generally solitary creatures. Mining bees are usually darker in color and smaller than the honey bees. Large, empty areas in the lawn provide the perfect site for the female mining bee to lay her brood. If the lawn has plenty of barren areas then this insect has been known to have more than one female nesting site. Males are seen in the spring hovering close to the ground which often catches our attention. These bees are important pollinators and the site selection must have an abundant source of flowers to provide nectar. Mining bees are not aggressive and rarely sting unless provoked, unlike the yellow jacket wasp which has been known to sting numerous times. These valuable creatures are a normal spring occurrence and we would not recommend an application of any chemical to control them. The entrance holes to the burrow are about ¼ inch in diameter and the bees will often create small mounds of sand in order to excavate the burrow. Some people assume the bees are damaging the grass or grass roots but the real truth is the lawn started out weak. In your case, it probably died as a result of the freezing temperatures this past winter. Once the grass dies and leaves an area with no vegetation the mining bees take advantage. The best control is to have a healthy, thick lawn. Remember to use slow release nitrogen lawn fertilizers with a 1:0:1 or 2:0:1 (N-P-K) configuration. The mining bee is one of those examples of “grin and bear” it which require no action from you.
Q: What are these small dark bees coming in and out of the ground in my lawn?