Exodus 8:24

And Pharao said, I [will] let you go, and do ye sacrifice to your God in the wilderness, but do not go very far away: pray then for me to the Lord.

And the dog-fly came in abundance into the houses of Pharao, and into the houses of his servants, and into all the land of Egypt; and the land was destroyed by the dog-fly.

And the Lord did so; and there came a grievous swarm of flies into the house of Pharaoh, and into his servants’ houses, and into all the land of Egypt: the land was corrupted by reason of the swarm of flies.