Answer:
Similes.
Step-by-step explanation:
Similes are the literary devices that writers use to enrich their works through the use of comparison words such as "like" or "as". It allows them to add more color to their work, giving them techniques that allow them to heighten the imaginative perception of their readers.
In the first sentence, "the men at the windows" are compared to "birds of prey" who swoop in to attack and devour their victims. Likewise, the second sentence also contains a simile for it uses "as" to compare "the miserable people" and "every green leaf, every blade of grass and blade of grain". Both sentences use the comparison word "like" (sentence 1) and "as" (sentence 2).
Thus, the literary device used in the sentences is a simile.