Squalers' function in a novel can be quite diverse. They could be a symbol of something, a plot device to drive the story forward, or a character that influences the main characters' decisions. It's hard to generalize without knowing the specific novel context.
Well, the function of squalers in a novel can vary. Sometimes they might be used to introduce conflict, at other times they could serve as a source of background information or even as a distraction to mislead the reader. It really all comes down to the author's creative choices.