User blog comment:Drayco90/Galaxy Under Siege- The Invasion of Cybertron/@comment-991605-20120315221048/@comment-143604-20120316002259

The Reapers are beyond the comprehension of the Transformers, so they can't scan them. Even if they could- "We are each a nation" or more acurately, a species- each reaper is technically a mechanical shell for an organic species and require them to work right.