swarm, cloud -- (a group of many things in the air or on the ground; "a swarm of insects obscured the light"; "clouds of blossoms"; "it discharged a cloud of spores")
Overview of verb swarm
The verb swarm has 2 senses
teem, pullulate, swarm -- (be teeming, be abuzz; "The garden was swarming with bees"; "The plaza is teeming with undercover policemen"; "her mind pullulated with worries")
pour, swarm, stream, teem, pullulate -- (move in large numbers; "people were pouring out of the theater"; "beggars pullulated in the plaza")