Exodus 8:16-17

16Then the Lord said to Moses, ‘Say to Aaron, “Lift up your stick and hit the dirt on the ground. It will become gnats in the whole land of Egypt.” ’

17Moses and Aaron obeyed God. Aaron lifted up his hand and he hit the dirt with his stick. The dirt became gnats that flew onto all the people and onto all the animals. The dirt on the ground became gnats all over Egypt.