What was the fourth plague of Egypt?
Flies
Else, if thou wilt not let my people go, behold, I will send swarms of flies upon thee, and upon thy servants, and upon
thy people, and into thy houses: and the houses of the Egyptians shall be full of swarms of flies, and also the ground whereon they are.
....
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.
Exodus 8:20And the LORD said unto Moses, Rise up early in the morning, and stand before Pharaoh; lo, he cometh forth to the water;
and say unto him, Thus saith the LORD, Let my people go, that they may serve me.
Else, if thou wilt not let my people go, behold, I will send swarms of flies upon thee, and upon thy servants, and upon
thy people, and into thy houses: and the houses of the Egyptians shall be full of swarms of flies, and also the ground whereon they are.
....
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.
Exodus 8:20