Symbolism, Imagery, Allegory
Someone get the Raid, because there are lots of creepy crawlies in Great Expectations—like the spider community that lives in the twenty-five-year-old wedding cake in Miss Havisham's dining room, or the beetles by the fire, and mice behind the walls.
I saw speckle-legged spiders with blotchy bodies running home to it, and running out from it, as if some circumstances of the greatest public importance had just transpired in the spider community.
I heard the mice too, rattling behind the panels, as if the same occurrence were important to their interests. But the black beetles took no notice of the agitation, and groped about the hearth in a ponderous elderly way, as if they were short-sighted and hard of hearing, and not on terms with one another. (11.55-56)
If Miss Havisham has transformed her house into a tomb, with its boarded up windows and lack of sunlight, then we can only guess (oh, yes) that these creatures are indicative of the decomposition that accompanies death. They're also, creepily, the only living things about the house. Yummy! Pay attention to other moments where bugs feature largely. Remember the night Pip spends at the motel in Covent Garden?