1, crayfish contain a lot of bacteria and parasites, but they are basically in the head. Therefore, when eating, you must go to your head. Never covet to save money and eat your head together. In view of the fact that the crayfish sold in most restaurants are basically headed, you must go to the head before eating. 2, the shrimp line must be removed, this part is the second dirty place behind the head. Many restaurants don't tear down the shrimp line in order to save trouble. I suggest you buy as many as possible and make them yourself. 3. Wash crayfish carefully. The crayfish sold outside, it is impossible for merchants to give you a particularly careful cleaning in order to save trouble, and many unscrupulous merchants will use shrimp washing powder to clean crayfish, and the residual shrimp washing powder is quite harmful. 4, cooking time should be sufficient, not less than 20 minutes. In order to save fuel cost and time cost, a lot of cooking time is not enough, which is a health and safety hazard. 5. When eating crayfish, if you find that the lobster's tail is straight, then these lobsters are dead shrimps, so don't eat them. If it is curved and curly, it means it is live shrimp, edible and nutritious. Crayfish head does contain a lot of bacteria and parasites, but it is by no means so sensational as social rumors, and it is not like foreign rumors that no one eats it. It is used to treat sewage, and it is edible as long as it is properly treated and cooked. -The parasites in crayfish can survive in the human body for many years, and at the same time, they will swim all over the body, which will bring harm to tissues and organs wherever they swim. Because crayfish mainly live in paddy fields, gullies and dirty water with poor water quality, parasites such as paragonimiasis are easy to attach to lobsters. In addition, other aquatic organisms can also be carried. The key to prevent parasites is to cook thoroughly. When making crayfish, it is not necessary to burn it to 100℃, but it can kill parasites at 60℃ to 70℃ for more than 5 minutes.