'Swarms' in the Bible

But if you will not let My people go, then I will send swarms of flies against you, your officials, your people, and your houses. The Egyptians’ houses will swarm with flies, and so will the land where they live.

And the Lord did this. Thick swarms of flies went into Pharaoh’s palace and his officials’ houses. Throughout Egypt the land was ruined because of the swarms of flies.

“As soon as I leave you,” Moses said, “I will appeal to the Lord, and tomorrow the swarms of flies will depart from Pharaoh, his officials, and his people. But Pharaoh must not act deceptively again by refusing to let the people go and sacrifice to the Lord.”

The Lord did as Moses had said: He removed the swarms of flies from Pharaoh, his officials, and his people; not one was left.