Animals have a way to make babies just like humans do. But instead of a mommy and a daddy getting married and then having babies, animals can have babies without getting married.
When two animals like each other very much, they might go through a special process called mating. This means that the boy animal (also called a male) will put his private part (also called a penis) inside the girl animal (also called a female) and release a special liquid called sperm. The sperm will then swim up to the girl animal's eggs, which are inside her body.
If one of the boy animal's sperm meets with the girl animal's egg, then they can make a baby together. The baby will grow inside the girl animal's body until it's ready to come out.
Some animals have different ways of mating. For example, some animals lay eggs and then the boy animal will release his sperm on the outside of the eggs. Others might rub against each other until they release their sperm and eggs, which can combine to make a baby.
Animals also have different preferences when it comes to mating. Some animals only like to mate with animals of the same sex, while others only like to mate with animals of the opposite sex. Some animals might even change their preferences throughout their life.
Overall, animal sexuality is just a way for animals to make babies and continue their species.