1. It is a common endoparasite in the intestine of human beings.
2. Body worm-like and has pseudo-segmentation.
3. The females are larger and stouter than males and measure about 20-30 cm in length, whereas males reach to about 15-26 cm in length.
4. Mouth is having 3 distinct lips.
5. Pharynx has few caeca but no posterior.
6. The posterior end of female is straight and that of male is curved.
7. Male bears a pair of sub-terminal Denial setae at post end.
8. Body is marked with four longitudinal canals or lines which run along the whole body length.
9. Excretory pore lies near the anterior end and the female genital opening lies near the middle.
10. The fertilized eggs pass out with faeces and hatch into embryos in warm and moist soil and infection occurs through contaminated hands and drinking water.