* Alliteration: The repetition of the "r" sound in "ragged" and "roamed" creates a sense of rhythm and emphasis.
* Assonance: The repetition of the short "a" sound in "ragged", "bands", and "raomed" creates a sense of unity and cohesion.
* Imagery: The phrase itself creates a vivid image of small, poorly-equipped groups of people wandering through the forest. This image contributes to the overall atmosphere of the book, which is often bleak and desolate.
In addition to these three devices, the phrase also uses figurative language by referring to the humans as "bands" which implies they are organized and unified. However, the word "ragged" undercuts this idea and suggests they are actually vulnerable and disorganised.
Overall, the phrase "ragged little bands that roamed the forest on foot" effectively uses several poetic devices to create a memorable and evocative image of the humans in *Grendel*.