Digging
It is the method used by “illegal diggers”, usually at night but also during the day, when the search is prohibited and maybe in fenced truffle beds not owned by them.
Sometimes, when you hunt truffles by the dog, after finding a truffle you continue to dig the soil around rather than stop and close the hole, this is also a method similar to the incorrect and damaging digging.
It destroys the mycelium and the roots of truffle, often collecting truffles immature.