Are they flying around or actually getting forced out, trying to get back in, then forced out again? Last year, a lot of drones were in an out of their own accord right before the hive swarmed.
If they are getting forced out, I'm too new to know. I would wonder, though, if some hives sometimes end up with more drones than absolutely necessary, or if unexpected weather/foraging issues would lead them to pare down the reproductive ranks to free up some food for the brood...