Animal behaviorists commonly refer to predatory killing as the “quiet bite” because it is never done in a fit of rage. Furthermore, extensive brain research shows that the rage circuits in the brain are shut off during a predatory hunt.
In her Bestselling book, Animals in Translation, Temple Grandin, Ph.D., explains that attacks meant to kill for the purpose of feeding are nothing like the growling, loud encounters that animals have when trying to protect themselves or their territory:
“We know from observation that the killer on the hunt is always quiet and expressionless.”
This evidence reinforces an existing theory that zombies likely don’t have the rage-filled and growling facial expressions seen in most fictional depictions (see: Zombie Don’t Snarl).
It also adds weight to the argument that zombies likely don’t moan. Grandin states clearly that animals on the hunt have no strategic reason to make any sound. In fact, noise puts them at a marked disadvantage, and so is avoided at all cost.
So remember, just because the zombie at you front door isn’t moaning and growling doesn’t mean it’s not interested in eating you alive. On the contrary, it may be more focused on just that than even the most realistic Hollywood ghoul.