Exodus 8:17

8:17 They did so; Aaron extended his hand with his staff, he struck the dust of the ground, and it became gnats on people and on animals. All the dust of the ground became gnats throughout all the land of Egypt.

Exodus 10:5

10:5 They will cover the surface of the earth, so that you will be unable to see the ground. They will eat the remainder of what escaped – what is left over for you – from the hail, and they will eat every tree that grows for you from the field.