"From the palm of your hand, it looks like a' dry stick' bitten by a bug ..." This may explain why it is difficult to detect internally. (Worm means small and not easy to detect. Drilling means drilling inside)
"Dry wood and dried meat" are all dry and lack of water, which may indicate that interpersonal disharmony leads to friction. If we pay attention to the harmony of interpersonal relationship in our life, it can be avoided.