Nematodes are also known as round worms. They live in soil and water as well as a host such as humans, plants, and animals. There are about 15,000 different kinds of nematodes known. The female can lay up to 200,000 eggs daily, though not all are fertilized. These roundworms eat algae, plant roots, and bacteria. They can kill its host if they are not removed. Females tend to cause a larger problem since they are larger and can lay many eggs. Being able to tell a female apart from a male nematode is difficult and may require placing them under a microscope in order to tell the difference.
Notice the size of adult male and female nematodes. The adult male nematode is smaller than the adult female nematode by a little more than an inch. The female nematode can grow up to 11 inches. The female nematode is wider than the male by half an inch.
Look at the tail of nematodes. The males have a bent tail. The female has a straight tail. Male nematodes use their bent tail to hold female nematodes during intercourse.
Notice how adult female nematodes attract males. Female nematodes give off a pheromone. This is a chemical or scent that is given by the female to attract male nematodes.
Analyze male and female nematodes under a microscope. The adult male has spicules that are needle shaped toward the middle of the body. The spicules serve the purpose of reproducing with female nematodes.