Final answer:
The figure of speech in the given sentence is personification.
Step-by-step explanation:
The figure of speech in the given sentence is personification. Personification is a figure of speech in which non-human objects or abstract ideas are given human characteristics. In the sentence, the day boys' grunts are described as being behind the main character and hurrying towards the screen. Since grunts cannot physically move, the use of personification provides a vivid and engaging description.For example, expressions such as 'the metal ramrods flashed all at once in the sunshine' and 'the long glowing trail' of the fish are visually evocative and charge the scene with tension and danger. The use of figurative language powerfully communicates the characters' intense emotional experiences and the dynamics of their environment.