For what reason does Grendel attack Herot?

The most obvious motive for Grendel's attack is envy and a sense of exclusion.

Explanation:

He hears the laughter in the mead-hall, hates the Danes and their merry-making from which he is excluded, and resolves to kill them. Even slaughtering thirty does not satisfy him and he returns night after night to drown his misery in blood.

judy jones is an attractive woman who receives attention from many men throughout the story.   despite her beautiful appearance, she is superficial and callous.   she is an aggressive woman who goes after any man she desires but she is not happy.   she is fickle and is never satisfied.   her beauty is only skin deep.   dexter breaks down because he knows his dreams are unattainable.   he believes that wealth and physical beauty are what will make him happy.   he soon realizes that she has lost her attractive looks.   it is not all what he had planned.