Synonyms for Swarm (same or very similar meaning)
WordNet sense 1 (a moving crowd):
drove, hordeWordNet sense 2 (a group of many insects):
cloudWordNet sense 3 (be teeming, be abuzz):
teem, pullulateWordNet sense 4 (move in large numbers):
pour, streamFrom the ODE community, based on WordNetadd/edit