How animals reproduce

Reproduction means to have babies or offspring. Plants and animals both need to reproduce in order to survive but they do this in different ways.

Animals need a male and female to reproduce.

Together they can create offspring or babies when they mate. This is called sexual reproduction.

Some animals, such as most fish, amphibians, birds and reptiles, lay eggs which contain their offspring.

The babies of most mammals grow inside the parent until they are developed enough to be born.

• Seahorses are the only species where the male gives birth.

• After a male and female praying mantis have mated, the female eats the male to provide nutrition for nurturing her offspring.

• Marsupials, such as kangaroos or koalas, keep their offspring in pouches on their stomachs for up to eight months.

• In a grey wolf pack, it is usually only the male and female alpha who are allowed to breed.

• The Virginia opossum only carries its young for twelve days, the shortest gestation (birthing) period in mammals.

• An African elephant's gestation period can last up to 22 months.

• Giraffe young can walk within thirty minutes of being born.

• Ostriches lay the largest egg of any bird. It is the size of around 24 chicken eggs.

For sexual reproduction to create a baby, there needs to be a male and a female.

1. The female parent has eggs.
2. The male parent has sperm.
3. An egg and sperm together. This is called fertilisation.
4. After fertilisation, one or more babies begin to grown, either inside eggs which are laid or inside the parent.
5. Once the baby is developed enough, it hatches from the egg or is born.

Viviparous animals give birth to live young.

Oviparous animals lay eggs.

Explore different animal groups below to find out which they are.

Did you know?

Asexual reproduction only needs one parent, instead of two and the parent makes its offspring by making an identical copy of itself.

Many small single-celled organisms like bacteria, reproduce asexually.

The number of offspring that an animal can give birth to is different for each species.

Larger mammals, such as humans, dolphins, giraffes and whales will only usually have one or two babies at a time. This is because these animals are more likely to survive and grow into adults because they are not eaten as prey by other animals.

Smaller mammals, like dogs and cats can have around five or six offspring in one litter.

There are some animals that can have many, many more offspring.

Some species of turtles can lay around a hundred eggs at a time and some fish can lay thousands of eggs in one go!

The length of time it takes for a baby to grow and develop varies depending on the species of animal.

In mammals, the time from fertilisation to birth is called the gestation period.

In humans this is around nine months, in elephants it can be around 22 months, and for a Virginia opossum just twelve days!

Fertilisation – Part of the reproduction process when a male and female cell s together to create offspring.

Gestation – The time between fertilisation and being born.

Offspring – An animal's babies or young.

Oviparous –Animals that lay eggs, in which their babies grow and develop until ready to hatch.

Reproduction – The process an animal uses to create its offspring. Reproduction can be sexual or asexual.

Sexual reproduction – When a male and female animal mate, they can create offspring or babies.

Viviparous – Animals whose offspring grow and develop inside the parent until the parent gives birth and the baby is born.

You may need pencils and paper for this activity.

1. Cut out fifteen squares of paper.
2. Write three examples of fish on three separate pieces of paper, then do the same for reptiles, birds, amphibians and mammals.
3. Mix all the pieces of paper up.
4. Try to sort them into two piles as quickly as you can – those that lay eggs and those that have live babies.
5. Try again until you get a record time!

What other groups could you sort these animals into?