They have really shinny eyes ...
There is a more dedicated website here for the interested. But like they say:
Unlike honey bees, blue-banded bees are capable of hovering, which one would assume makes them easier to photograph. This couldn’t be further from the truth, and taking a clear photograph of a blue banded bee in flight is reason for celebration.took a bit of time to get even these shots with my FD300mm on my Panasonic GH1