The TravelBuzz board seems to be the most appropriate spot for my crazy question.

I live in a somewhat rural area of North Carolina. Every night a what sounds-to-be relatively small prop plane flies over my house at almost exactly 3 a.m. It's fairly low because I guess the engine noise wakes me. It might be in the range of a few minutes before 3 until a few minutes after, but it's just as regular as can be. I glance at the clock and sure enough, it's the 3 a.m. plane! I also think it's "trained" my body to wake at this time, because I'll often wake by myself about 5-10 minutes before 3 a.m., and find that's a good time to get up and use the restroom. Without fail, the plane is overhead in no time.

What is the plane doing? I understand commerical travel and am in tune with all the early morning take-offs at RDU, which start about 6 a.m. Who is flying at 3 a.m. with such regularity? Why do people fly in the middle of the night? Is someone commuting to someplace every day? Are they delivering something? Is it less expensive to take flying lessons at night?

Hope someone can settle my curiousity!