Girls have a certain fishy smell, mainly because they contain a special protein - peroxidase. When the skin of the fruit is damaged, the peroxidase will react with oxygen in the air to produce a substance with a bloody smell, causing the fruit to have a fishy smell. In addition, if pesticides are used during the planting process of the girl's fruit, it may also cause the girl's fruit to have a bloody smell. In order to avoid eating guava with a bloody smell, it is recommended to choose fruits with an intact skin, no spots, and a firm feel, and wash the guava before eating.