I have a lot of green flies that live in the ground. They have many holes , in the sand of my flagstone path, that they go in and out of of the holes all day, more so in the morning. They have bright green bodies, it looks like they are collecting pollen because some have a lot of yellow powder on there back legs. They are not causing any problems they are actually really fun to watch I just wanted to know what they are doing in there underground world.
Metallic Sweat Bees Agapostemon and Augochlorella species, have bright, usually green bodies and nest in the ground, digging tubular burrows. they are called Sweat Bees since they are often attracted by human perspiration. They do pollinate flowers.