Is Grendel's opinion on animals supported and moreover right

Grendel's mind is very pyramidal. He thinks in hierarchy and warfare. Within the beginning of the novel, Grendel encounters an angered bull while stuck in a tree. The bull's tactics for expressing it's discomfort is repetitive and therefore (to Grendel) meek and primal. Grendel internally compares animals to machinery because they do not respond to language and they don't recognize emotions and feelings. During the attack, Grendel thinks, "I bellowed at [the bull]. He jerked his head as if the sound were a boulder I'd thrown at him, but  then he merely stood considering, and, after a minute, he pawed at the ground again" (Gardner, 20). 

Does the bull's non-reaction to Grendel's screams insist and that animals are lower on the hierarchy than humans or monsters?
Is Grendel right for putting each type of creature on a different level of a pyramid?