How do people in the old days protect themselves from tunneling?

In ancient times, people protected themselves from tunneling, particularly in the context of warfare, by employing various strategies. They often constructed fortifications with deep ditches or moats to deter attackers from digging tunnels. Additionally, they might have used hidden traps or placed obstacles underground to detect or collapse tunnels. Surveillance and intelligence about enemy movements were also crucial in preemptively identifying tunneling efforts.