Factual error: The kids take shelter in a truck and whilst the monster is distracted they release the brakes and it starts rolling down a hill. The brakes would have been seized up due to lack of use so the kids wouldn't have been able to release them in the first place.
Suggested correction: Even if the brakes had seized, it's possible that the force exerted by the truck on the incline would "snap" them free. That's what happened.
Plot hole: So the monsters must be blind because they cannot see the people, and yet they seem to know where objects are, so they can grab them or avoid them. If they use some type of sonar then they would be able to locate people as well.
Suggested correction: This is an assumption. It's not explained how the creatures sense their environment. Just because something isn't explained, it doesn't make it a plot hole.