2. Crabs like to eat animal carcasses and rotten food, and their digestive tract contains a large number of pathogenic bacteria and other harmful substances that are harmful to human body. After the death of crabs, bacteria multiply and produce toxins. In addition, the crab contains more histidine, and histamine is a toxic substance. The longer the crab dies, the more histamine it accumulates. When it is accumulated to a certain extent, it may cause poisoning after people eat it. It is suggested that when eating crabs, they should be fresh and ripe, and avoid eating drunk crabs and cold-mixed raw crabs to avoid poisoning or infection with parasites. In addition, people who are allergic to crabs, patients with hyperuricemia and gout, pregnant women and other people should eat less or ban crabs.