1. Life cycles of
some animals

2. Questions to think about…
What are the stages of a life cycle?
What is a life cycle?

3. What is a life cycle?
All living things go through a cycle called a life cycle.
A cycle is a pattern that repeats itself continuously.
Living things may reproduce. They may have young while they are alive.
The young undergo the same life cycle as their parents.
This way, living things of the same kind continue to be found on Earth.

4. What are the stages of a life cycle?
A stage represents a step in the life cycle of a living thing.
Humans give birth to their young. The young and the adult are the stages in the life cycle of a human.

5. What are the stages of a life cycle?
An adult bird does not give birth to its young. It lays eggs instead. The egg, chick and adult bird are the stages in the life cycle of a bird.

6. What are the stages of a life cycle?
The stages in a life cycle are different for different living things.
In general, the stages are egg, young and adult.
The life cycle of a living thing shows the order of the different stages.

7. What are the stages of a life cycle?
Some living things look very similar at different stages.
Some look very different, like that of the ladybird below.

8. What are the stages of a life cycle?
Some animals have three-stage life cycles. Some examples are the cockroach and grasshopper.
Some animals have four-stage life cycles. Some examples are the butterfly, mosquito and beetle.

9. Life cycle of a human
Young (Baby)
The egg grows into a baby inside the mother until it is ready to be born.
The cycle repeats itself when the adult reproduces.
The young grows into an adult.
The life of a human begins as an egg.
Adult
Egg

10. Life cycle of a chicken Egg Adult
The hard shell prevents the egg from drying out, and protects the growing animal inside.
A chick looks a lot like its parents. As it grows, it looks even more like its parents.
The adult chicken is able to reproduce and a new life cycle begins.
The egg has a hard shell as its outer covering.
A chicken begins its life as an egg.
Young (Chick)

11. Life cycle of a frog
Egg
When a tadpole grows into an adult frog, it does not have a tail and gills anymore.
The frog breathes with its lungs and skin instead.
Known as a tadpole, it has a tail and breathes through its gills.
An adult frog is able to reproduce.
The young of a frog looks very different from its parents.
The egg is covered with a jelly-like substance.
A frog’s eggs are usually laid in water.
Adult
Young (Tadpole)

12. Life cycle of a cockroach
Egg (in egg case)
Adult
Nymph
A nymph looks similar to the adult, except it is smaller and does not have wings.
A nymph moults a few times as it grows, before becoming an adult.
The egg case is left in a dark and safe place for the eggs to hatch on their own.
A female cockroach lays its eggs in an egg case, which can contain 16 to 50 eggs.
An adult cockroach has wings. If it reproduces, a new life cycle starts.
Each egg hatches into a small cockroach called a nymph.

13. Life cycle of a grasshopper
egg
Adult
An adult grasshopper can lay about 20 to 120 eggs in the soil each time.
Nymph
A nymph moults several times. It grows into an adult grasshopper which has wings.
A nymph looks almost the same as its parents, but it is smaller and has no wings.
The cycle repeats itself when a female adult lays its eggs in the soil.
A grasshopper starts its life as an egg.
Each egg hatches into a nymph.

14. Life cycle of a butterfly
Egg
Adult
Larva (Caterpillar)
A caterpillar grows very fast. As it gets too big for its skin, it grows a new skin and sheds the old one. This is called moulting.
Each egg hatches into a larva. The larva of a butterfly is called a caterpillar.
When it is time for the caterpillar to change into a pupa, it stops feeding and hooks itself to a leaf or a twig.
When the case breaks open, an adult butterfly appears. It spreads its wings to dry before flying off.
The pupa may look still but many things are taking place inside.
The female butterfly may lay eggs on another plant, starting a new life cycle.
The caterpillar moults a few times as it grows bigger.
The butterfly lays its eggs on the leaves or stem of a plant.
It then flies off and leaves the eggs to hatch on their own.
Pupa

15. Life cycle of a mosquito
Egg
Larva (Wriggler)
Adult
A mosquito larva is called a wriggler. It lives in water. It moults several times as it grows.
When the case breaks open, an adult mosquito appears. It waits for its wings to dry before flying off.
The cycle repeats itself when a female adult mosquito lays its eggs.
It stops feeding and changes into an adult mosquito in the pupal case.
A mosquito larva develops into a pupa which lives near the water surface.
The oval-shaped mosquito eggs are laid in still or slow moving water.
Pupa

16. Life cycle of a beetle Egg Adult Larva
It stops eating and slowly changes into an adult ladybird beetle in the pupal case.
The cycle repeats itself when a female adult ladybird beetle lays its eggs.
A ladybird beetle larva lives on plants. It moults several times as it grows.
When the pupal case breaks open, an adult ladybird beetle appears.
A fully grown ladybird beetle larva develops into a pupa.
Ladybird beetle eggs are laid in small clusters on leaves.
Pupa

18. The end