Exodus 8:5, 17

And the LORD said to Moses, “Say to Aaron, ‘Stretch out your hand with your staff over the rivers, over the canals and over the pools, and make frogs come up on the land of Egypt!’”

And they did so. Aaron stretched out his hand with his staff and struck the dust of the earth, and there were gnats on man and beast. All the dust of the earth became gnats in all the land of Egypt.