Pocket Genius Science: The living world – Animal reproduction

Facts At Your Fingertips: The living world – Animal reproduction

Animals use different methods to reproduce (have babies). The young of some species develop inside eggs laid by the mother, while other species give birth to live young.

Some have many young, most of which will be eaten by predators, while others produce a few offspring that they look after carefully.

Laying eggs

Many animals lay eggs. Fish and amphibians lay their eggs in water. Their eggs do not have shells and are soft.

Reptiles’ eggs have leathery shells, while birds’ eggs have hard shells. The shells protect the eggs and stop them from drying out.

The baby reptiles or birds must break through the shells when they hatch

Eggs galore

Some animals, including many amphibians and fish, lay thousands of eggs. They leave the eggs, so the young have to fend for themselves as soon as they hatch.

Most of the eggs and young will be eaten before they grow up, but a few of them survive to adulthood.

Live young

Most mammals give birth to live young.

The babies develop inside their mothers and receive all the nutrients they need to grow from their mother’s blood. After they are born, the young feed on their mother’s milk as they continue to grow.

Looking after babies

Some parents look after their young for months or even years after they are born. The parents bring food for the young and teach them the skills they will need to survive.

Lions live in groups and help each other care for the young.