A flurry of activity and commotion is often referred to as bustle. If you want to see true bustle in action, just walk through Times Square in New York during lunch hour.
If it's busy, energetic or moving about at a rapid pace, then it's bustling. Word historians think bustle might stem from an Old Norse word meaning "to prepare." However, it's probably easier to remember bustle by the synonym it's often used with — hustle, as in "the hustle and bustle of a big city."