light sleepers?

I suspect that the guy killed by the car desperately trying to warn the world about what was happening and that middle aged man running terrified earlier in the movie with pod shrieking in the background both either witnessed a pod developing or were light sleepers who like Donald Southeland later in the movie woke up to their own pods developing.

There were likely others who reported incidents frantically to the cops but either the cops they reported to were already pods or if not just assumed the people were nuts.

I would like to think I would wake up if a pod was developing near me but its possible that they do not make as much sound as you would think. I wonder if when the process starts the pods drain some of your biological energy making it harder to wake up, which would help with light sleepers? Maybe the effect is mild like when you eat turkey or take an OVER THE COUNTER (not prescription) sleeping pill. For example Nancy was able to wake Matthew when she frantically yelled but she had to yell VERY loud, louder than I think you normally would to wake a person.