The Russians, in adapting their strategies to counterpoint nato gid tier artillery precision and drone effectiveness, they are going fully underground, tunnels, like the Korean War.
A 160 meter long tunnel, big enough for a man, dug with traditional digging tools and a makeshift conveyor belt bucket brigade, was found. It was used to get underneath a Ukraine position from a russian position, and hand carried time delay artillery can disable equipment and positions Ukraine side.
Src:
https://youtu.be/9Ck2Ls9mtJQTldr: Russian soldiers going all underground. Send ground wave sonar and similar bullshit.
