Just read this on the wiki, I think it's the databook explanation of the jutsu:
Depending on the location of the fight anyone who can use hiding like a mole can counter the hidden mist jutsu. People should keep this in mind during Kakashi vs Mei or Zabuza fights. Although Zabuza can still hear him idk about Mei tho.
Hiding like a mole technique: This technique changes earth into fine sand by channelling chakra into it, allowing the user to dig through it like a mole. This effect goes around the body (not just the hands), making it just large enough for a person to move through. The user can pinpoint where they are, despite being underground, by sensing the magnetic forces. They can also sense what is happening on the surface and use that information to launch a surprise attack on the enemy.
Depending on the location of the fight anyone who can use hiding like a mole can counter the hidden mist jutsu. People should keep this in mind during Kakashi vs Mei or Zabuza fights. Although Zabuza can still hear him idk about Mei tho.