What is the difference between a male earthworm and a female earthworm?

There are several differences between the male and female nematodes. Males usually have straight tails while the females have a curvier tail. Males are usually around 10 in., while females are usually around 11 in. Females also usually have bodies about a half-inch wider than the males. When looking under a microscope, the males have spicules on the center of their undersides.