Sperm is produced in the testicles, which are found in the scrotum. Each sperm cell takes about 72 days to grow, and they require a s
lightly cooler environment (around 3-5°F or 2-3°C below
body temperature) which is why the scrotum and testes are found outside the
body.
Sperm production begins during puberty, which usually occurs in boys between ages 9 and 15. The production of semen (the
milky fluid that carries the sperm) begins a few months before the
body is ready to produce the sperm itself. Production continues for the rest of the man's life; unlike women, who stop producing eggs sometime around age 40.