Some people often buy chicken heads to make stewed chicken heads or marinated chicken heads at home, thinking they are flavorful and delicious. But as the saying goes, "A ten-year-old chicken head is like arsenic." Chicken heads should not be eaten too much, otherwise it can cause poisoning. The reason is that in the process of pecking, chickens continuously store harmful metals in their brain tissue. The older the chicken, the more toxins it stores. Therefore, when eating chicken heads, you must pay attention to the chicken's age. Those that are 1-2 years old can be eaten in moderation, but not excessively.