Pain in the privacy of a 9-year-old boy may be caused by trauma, mosquito bites, circumcision and glans penis, urethral stones and other reasons. 1. Trauma: when the perineum of a 9-year-old boy is hit or stabbed, it may lead to damage or fracture of the epidermis of the penile scrotum and symptoms of pain. 2. Mosquito bites: If a mosquito bites the penile scrotum skin, due to the toxins in the mosquito salivary glands, after entering the skin, it may lead to penile scrotum pain, redness and swelling and other symptoms. 3. circumcision: if the 9-year-old boy’s foreskin is too long, circumcision, due to cleaning is not in place, bacteria may be generated in the foreskin, resulting in inflammation of the foreskin and glans. Under the stimulation of inflammation, the penis can show symptoms of pain. 4. Urethral stones: When a 9-year-old boy suffers from urethral stones, the stones will move with the urine and may cut through the inner wall of the urethra, resulting in penile pain. When a 9-year-old boy has penile pain, there may be other causes, and it is recommended to actively seek medical attention under the guidance of a medical professional.