He is upset at the Dane's happiness. It angers him that while they are happy, he is not. He also attacks because he is hungry and thinks of them as a "food supply" and wants revenge because he is jealous of their laughter and happiness.
Grendel attacks the Danes out of jealousy and revenge. He is angered by the merrymaking and happiness in Heorot, the mead hall, and feels isolated and excluded from the human community. Grendel's attacks are a way for him to seek retribution and assert his power.
Because he's angered with the happiness in Herot
becuz he stupid
The Danes wanted to be prepared for Grendel's attack. They would not have time to put on armour while the beast was attacking.
In Beowulf, the Danes irritate Grendel by celebrating loudly in the mead hall Heorot every night. Grendel, who is a creature of darkness, cannot stand the noise and the joyous festivities of the humans, causing him to attack the hall and kill its inhabitants.
Grendel's mother attacks the Danes in retaliation for the death of her son, Grendel, who was killed by Beowulf. She seeks vengeance for the harm done to her family and to protect her own kind from further harm. Her attack is driven by a desire for retribution and the instinct to protect her own.
The narrator describes Grendel's hatred for the Danes as "pain as raw as knuckles."
The Danes wanted to be prepared for Grendel's attack. They would not have time to put on armour while the beast was attacking.
Geat; Danes
Grendel terrorized the Danes for twelve years before being defeated by Beowulf.
Beowulf killed Grendel and he was a Dane, so yes
12 years
Beowulf is a legendary hero who travels from Geatland to help the Danes by fighting the monster Grendel.
Geat; Danes
Good vs. Evil