Escamilla claims that RODS are not birds. Rods are cigar or cylindrical shaped objects that travel at high velocities barely visible with the naked eye. They appear to be alive as they move through the air like fish swim in the sea. They appear to have fins or appendages along the torso and the torsos bend as they travel. The term Rods came along because these things had the impression of things you can see under the microscope that are called Rods.
Rods are common in the medical profession.
The word Rod can be found in Tabor's Medical Dictionary as cylindrical shaped bacteria. So for lack of a better name Rods kind of stuck. From the evidence we have gathered it doesn't seem to suggest that these are Alien or man powered vehicles. We just don't have evidence that would suggest space craft piloted by Aliens. Some are thin like spears.