Yup, those truffles are smart. Soon as they see the French border they pull up stakes and head for the interior.
Very few of us know anything about mushrooms and most of the threads that get interesting get locked for some reason. You should learn to pick with an expert and maybe limit yourself till you really know what you're doing to the eight or so species that are good to eat and so distinctive as not to be easily confused with ones that are deadly poisonous. One bad one in you spaghetti can take out the livers of the entire family. By the way, you die without a liver.