If it enters the digestive system of higher animals, most of it will be digested, but these nematodes have a certain chance of infecting people. For example, adults of iron nematodes live alone in water, occasionally infecting human bodies and causing filariasis. It is easy for us to drink these larvae of iron nematodes in pools and unclean water, and there is a certain chance of filariasis after drinking them. This disease can cause urinary tract infection and inflammation, so the water in the pond and unclean water should not be drunk casually.