Crabs can't be eaten after they die overnight, because there are many bacteria and toxic substances in dead crabs. If eaten, it may cause food poisoning, leading to abdominal pain, diarrhea, vomiting and other symptoms. Even crabs that have just died for less than 3 minutes are not recommended, because crabs are scavengers. After death, bacteria in the body will multiply rapidly, decompose protein and produce harmful substances such as histamine. Only live crabs are fresh, so as to ensure the taste and safety.