It is true that a vasectomy procedure is simpler than female sterilization surgery. It’s an outpatient surgery where a doctor blocks the vas deferens — the tubes that carry sperm from the testicles to other glands, where the sperm mixes with other fluids and become semen, the stuff that comes out when a man ejaculates. A man who has had a vasectomy still ejaculates, but because his vas deferens are blocked, his semen no longer contains sperm, and thus he can no longer get a partner pregnant. And vasectomies are indeed very effective — they have a failure rate of less than one percent.