In the living state, oysters breathe and absorb nutrients through their mouths. After death, their mouths will be bigger, their shells and meat will be separated, and they will have a very smelly taste. After death, oysters lose their ability to breathe and digest, which leads to the separation of shell and meat and spoilage. It should be noted that the opening and closing state of oysters in the cooking process does not mean life and death. The closed state means that the muscles of oysters tighten when heated, and the open state means that oysters have to breathe and absorb nutrients in the living state.