I see them often around the house. Recently learned that they prey on Carpenter Bee larvae, which we have in abundance.
Tiger Bee Fly flying around my front porch lights just before a thunderstorm. 10pm
This tiger bee fly was observed interacting with a second of the same species, as well as resting on a wooden table repeatedly over the period of about 15 minutes.
Xenox tigrinus (Diptera: Orthorrhapha: Asiloidea: Bombyliidae: Anthracinae: Anthracini). Burke, Fairfax County, VA 04 September 2012
I believe this is the species.
18 mm body length. Phragmites meadow.
A BIG fly, maybe 3/4 inch wide. Seen sitting on lamppost just inside entrance to Potter Park Zoo, Lansing, MI.
Checked Bugguide.net and the wing, abdominal and thoracic patterns look to fit Xenox tigrinus.