Ferrous nematodes are found in the tropics and temperate zones, live freely in water, and can occasionally infect humans by parasitizing the digestive or urinary tract. Adult wireworms are thread-like and dioecious, with females laying eggs at the water's edge, which hatch into larvae in the water that can live parasitically in the intestinal tract after being eaten by humans.
Additionally, when the human perineum comes into contact with a body of water with nematode larvae, the larvae can invade through the urethra and travel upward to the bladder to parasitize, and the worms invade the human body and further develop into adult worms that can survive for many years.