The significance of the 'insects'

Places were the presence of "insects" is made obvious (to the viewer), that I noticed/recall:

1) When Matt goes into the bathroom to say "Dead Mary" three times, he notices that the shutter is open and closes it. When he does, the viewer sees a mass of "insects" behind the shutter (on the outside of the cabin).

2) When the group is standing around the body of Matt in the woods, small "insects" can be seen crawling over his bloody corpse (sort of) along with insect-like sound effects.

3) When Baker (aka Bryce) shoves the gardening tool through Dash's neck (?) and through the shed wall, in addition to the blood you can see "insects" crawling around the hole left in the shed wall.

It seems awfully strange to so blatantly draw attention to the "insects" unless it's meant to be some sort of message to the viewer (e.g. "the 'possessions' are tied to the insects" or "the 'possessed' are rotting flesh complete with scavenging insects"). My problem with that, though, is that Eve seems to "possess" people by biting them or ripping them apart with her teeth (no "insects" to be found) and there's really nothing to suggest corpse-like qualities for the 'possessed.' Which leads me to believe that the insects were just meant to be "creepy" with no real connection to the plot as shown (i.e. it's just sloppy visual story-telling; not simply superfluous, but unnecessarily duplicitous). The red herring of the movie title/game in the movie (i.e. "Dead Mary" had nothing to do with the events of the film) I can forgive as being somewhat-novel movie sleight-of-hand, but the "insects" really bugged me for some reason (pardon the pun).