When Chris is describing the human condition after unveiling his sculpture, part of what he says is, "The worms crawl in, the worms crawl out." This is a reference to the song "The Hearse Song," also known as "The Worms Crawl In."
Joel calls dust mites 'microscopic bugs'. He then corrects Maggie, saying dust mites are arachnids not insects. To an entomologist, the word "bug" is a trigger. Dust mites are not bugs! Bugs (cicada, bed bugs, aphids, leaf hoppers) belong to the order Hemiptera, whose defining trait is their piercing/sucking mouthpart.