mill around
To loiter, wander around, or waste time idly (some place). I'll just mill around in the store across the street while you get your hair cut. There were a bunch of teenagers milling around near the entrance to the store, and it was making me a little bit nervous.
mill around
and mill aboutto wander or move around aimlessly within a small area. Everyone was milling around, looking for something to do. The students milled about between classes.