Sand Wasp

There are a lot of these always flying around the dunes of Key Biscayne. I never had gotten a good look at them as they are quite restless. I thought they may be a kind of fly, but turned out to be a small wasp. The markings are very faint yellow almost white and blend well with the sand color. In the second photo it is hovering over a hole that may be its nest or perhaps a neighbor. It landed near it on photo 3 and made a few digging motions before flying again. The area were it was digging looked like a mine field of Sand Burrs.