swarm 1 
(swôrm)
(swôrm)n.
1. A large number of insects or other small organisms, especially when in motion.
2. A group of bees, social wasps, or ants, when migrating with a queen to establish a new colony.
3. An aggregation of persons or animals, especially when in turmoil or moving in mass: A swarm of friends congratulated him.
4. A number of similar geologic phenomena or features occurring closely within a given period or place: a swarm of earthquakes.
v. swarmed, swarm·ing, swarms
v.intr.
1.
a. To move or emerge in a swarm.
b. To leave a hive as a swarm. Used of bees.
2. To move or gather in large numbers: Shoppers have swarmed into the mall.
3. To be overrun; teem: a riverbank swarming with insects. See Synonyms at teem1.
v.tr.
To fill with a crowd: sailors swarming the ship's deck.
[Middle English, group of bees, from Old English swearm.]
swarmer n.