A boy's testicles start off, during development, inside the abdomen. By the time he is born, they should be down in the scrotal sac. If a testicle is still not down by 6-12 months of age, it may need help getting down or may no longer be alive. If we leave it up high, it will not work properly, can twist around on its own blood supply, and is at a higher risk for tumors.