I was right down the middle on this movie - LOVED the performances and the family focus and the post-apocalyptic vibe.
But... HATED the stupid logic gaps and plot holes. Just super dumb, no real thought given to a movie that is SO rules dependent.
Like... why set up a waterfall where people can speak normally, even yell, in safety - then show them living in the quietest part of the region where they have to use sign language? Why not live next to the river/waterfall, even just to deliver and raise the baby. Just STUPID. Wouldn't everyone just go the coastlines to live where the sound of the ocean is loud?
What about a windy day? Wouldn't these creatures just go ballistic, running and trying to swallow every tree that has leaves blowing loudly?
How could animals ("aliens"?) that are basically just insect-looking lions with great hearing have taken over the whole world within a few months? They are very much ravenous animals, not even "sentient" intelligent aliens like in "Signs." Why did the news article on the wall describe them as "indestructible" yet she can kill one with a standard rifle? For an animal that hunts solely with super-sensitive hearing, why didn't anyone figure out before that a super-loud sound like audio feedback would incapacitate them?
Even smaller questions became infuriating by the end:
Why use sign language when it would be safe to softly whisper inside a house (where the gentle sounds of the trees blowing outside would be louder)? Where is the wider community - why is there no one else around when you have a sizable family living in some security? Why are the creatures so absent and disatnt in the first third/half of the movie but seemingly walking inside the house in every scene in the second half, when nothing really fundamental has changed?
Why wouldn't you just set up bells triggered by long ropes to safely move around - drawing any nearby creatures out into the open, and you could shoot them with the rifle?
Cool concept in theory but something that doesn't hold up to even the most basic scrutiny.
Spoiler: 
