Crabs that have been dead within two hours are edible. At this time, the number of bacterial growth in the crab is not very large. After high-temperature cooking, the parasites and bacteria in the crab can be effectively killed, thus not causing excessive impact on the human body. However, generally do not eat dead crabs that have been more than two hours old. At this time, a large number of heat-resistant bacteria breed in the crabs, which cannot be completely killed by heating for more than 20 minutes. Ingestion into the human body may cause abdominal pain and diarrhea. Phenomenon.