Why do cows scream at night?
They are scared
One of the most common reasons why cows moo at night is because they do not feel safe, either by humans or predators. If they find their predators such as coyotes, mountain lions, and wild dogs prowling under the cover of darkness, cows will moo loudly to alert danger to the rest of the herd.
What do cows hate?
They will retreat because they hate high-pitched sounds. If your pet dog barks at them, they will also withdraw from the grass as barking is also a high-pitched sound that they hate. According to research, cows have a perimeter of space around them, which, if you get into, they retreat.