swarm out (of something or some place)
To move out (of some place or thing) very quickly and in great numbers. Students swarmed out the moment the final bell of the year rang. Bees began swarming out of the hive after we accidentally hit it with a baseball.
swarm out of something
to move out of something in great numbers. The bees swarmed out of the hive. People swarmed out of the park at the end of the game.