mushi no shirase
an insect’s message/notification
a premonition; a sign of something bad about to happen; the sixth sense
In the old days, an insect was believed to be in your body that gives you a premonition. This phrase is often used when you have a premonition of someone’s death, as in the example sentence below.
Suddenly, one of my old friends appeared in my dream, and later I found out he had passed away on that day. It would have been the portent of the unfortunate incident.