Observe how they adapt to and behave in their environment. Different parts have different functions, but all of the parts work together to help the animal survive. Some parts are responsible for allowing the animal to reproduce. The reproductive organs on an animal also determine its gender. Often, male and female animal anatomy varies.
Earthworms are hermaphrodites , which means that they have both male and female reproductive organs.
Their eggs and sperm are released in a protective mucus sheath which slips over the worm's head and is deposited in the soil. If you didn't find the answers to your life science questions, try searching Ask A Scientist . If you still have questions, send them to Ask Living Things .