Back when the idea that life began at conception was considered a heresy humans were the only creatures declared to have souls, and God put them in at quickening. Life beginning at conception was added around the fourth century to justify God sending unbaptized babies to Hell. Since a soul is needed to leave behind a ghost the early church would have ruled no ghost bugs. While the position on origin of soul has shifted I suspect bugs aren’t recognized as having souls.
Back when the idea that life began at conception was considered a heresy humans were the only creatures declared to have souls, and God put them in at quickening. Life beginning at conception was added around the fourth century to justify God sending unbaptized babies to Hell. Since a soul is needed to leave behind a ghost the early church would have ruled no ghost bugs. While the position on origin of soul has shifted I suspect bugs aren’t recognized as having souls.