The life cycle of Taenia tapeworms begins when eggs or gravid proglottids are released from an infected host into the environment. Intermediate hosts, such as cattle (T. saginata) or pigs (T. solium), ingest contaminated vegetation. The eggs hatch into oncospheres, which penetrate the intestinal wall, travel through the circulation to muscles, and develop into infective cysticerci. Humans, the definitive hosts, become infected by consuming raw or undercooked meat containing these cysticerci. In the human small intestine, the tapeworm's scolex attaches to the intestinal wall, where it develops into an adult worm.