The Deer at the beginning.
Why would the creatures kill the deer? Do they just kill every living thing in the area?
Should the deer not have been infected like the husband and dog then and become one of them? Or at least 'dissolve' in the sunlight.
If they don't want humans in the hollow then they shouldn't be leaving great big clues around the forest of they're existence!!
The film had a great premise, but was a bit lazily handled.