As soon as we got out of the car, clouds of gnats and black flies swarmed around our heads.

He felt as though clouds of frenzied moths swarmed within him, seeking a light they couldn't find.

But as I watched, I could see this cloud was not swarming in any ordinary sense.

The clouds of insects swarmed still, though they might be different insects.

A gray cloud of insects swarmed above a broken depression in the weeds.

The whole cloud would have been swarming with ships, and we'd have been finished.

Within days, clouds of flies formed and swarmed over nearby homes.

Great dark clouds of the insects swarmed over patches of green which disappeared in their wake.

Swollen, black clouds swarmed overhead, pouring down massive quantities of rain.

A cloud of flies, swarming over the bodies.