'Swarms' in the Bible

If you do not release my people, then I am going to send swarms of flies on you and on your servants and on your people and in your houses. The houses of the Egyptians will be full of flies, and even the ground they stand on.

But on that day I will mark off the land of Goshen, where my people are staying, so that no swarms of flies will be there, that you may know that I am the Lord in the midst of this land.

The Lord did so; a thick swarm of flies came into Pharaoh's house and into the houses of his servants, and throughout the whole land of Egypt the land was ruined because of the swarms of flies.

Moses said, "I am going to go out from you and pray to the Lord, and the swarms of flies will go away from Pharaoh, from his servants, and from his people tomorrow. Only do not let Pharaoh deal falsely again by not releasing the people to sacrifice to the Lord."

and the Lord did as Moses asked -- he removed the swarms of flies from Pharaoh, from his servants, and from his people. Not one remained!