From Insectidentification.org (abridged): "Non-aggressive wasps that tend to mind their own business sipping on flower nectar during the summer. Early in spring females prepare to lay eggs. A female will dig into soil, create many deep tunnels, and cover them to hide their existence. Then she will track a small insect and sting to paralyze it, but not to kill. She will clutch it using her antennae and mandibles and fly it back to the tunnels. It is not uncommon to see birds (robins or tanagers) attempting stealing her prey by chasing her until she drops it. No other species of digger wasp is known to be harassed by birds this way. If the female is successful in returning to her tunnels with her catch, she will place the paralyzed prey aside to quickly inspect a tunnel. If it looks intact, she will pull the paralyzed insect, head first, down into it. She then lays an egg on the insect, exits the tunnel, and covers it over again. She repeats this process for each tunnel. Unlike other wasps, she does not actively defend her nest. Once hatched, the wasp larvae will feed on the living immobile insect."