He, a descendant of Cain, has been exiled into darkness: “Conceived by a pair of those monsters born/ Of Cain, murderous creatures banished/ By God, punished forever for the crime/ Of Abel’s death” (20-23). Therefore, as a foe of God, Grendel is angered at the fact he cannot exist in light. Given that he cannot enact his revenge upon God himself, Grendel enacts his revenge upon God's people. Other reasons why he may attack humans is that the text also specifically says that he can't stand the noise of the "harp’s rejoicing"(4) in the mead hall. Grendel is perhaps attacking because the joyful camaraderie reminds him each day of his own isolation -- owing to his connection to the Biblical Cain. He is described as child-like. Young children will lash out when they are frustrated or don't like what is going on. If a noise is too loud, they might just cry, but they might hit the person making the noise. Of course, children don't react this way out of violence or evil, but rather out of a lack of self-control. Grendal is both child-like and evil. He is unable and unwilling to control himself. His reaction to the joyful noises he hears in the hall begins as a lack of self-control and continues as an evil act of anger and vengeance against the…