'Gnats' in the Bible

And Jehovah said to Moses, Say unto Aaron, Stretch out thy staff, and smite the dust of the earth, and it shall become gnats throughout the land of Egypt.

And they did so; and Aaron stretched out his hand with his staff, and smote the dust of the earth, and there arose gnats on man and on beast: all the dust of the land became gnats throughout the land of Egypt.

And the scribes did so with their sorceries, to bring forth gnats; but they could not. And the gnats were on man and on beast.

He spoke, and there came dog-flies, and gnats in all their borders.