The cockroach has three stages in its life cycle.
The female cockroach lays many eggs in a dark and safe place. The eggs are then left to hatch on their own. Each egg hatches into a baby cockroach called a nymph. A nymph looks similar to an adult cockroach, but it does not have wings.
The nymph eats waste like leftover food, paper, cloth, etc. As it eats, it grows big. The nymph sheds its outer skin many times as it grows and becomes an adult. This shedding of skin is called moulting.
THE LIFECYCLE OF A FROG
Frogs are amphibians; they live both on land and in water. The female frog lays hundreds of eggs in water.
These eggs hatch to release the tadpoles. A tadpole is different from frog. A tadpole can live only in water. It has feather-like gills to breathe. It has a tail but no legs. A tadpole eats weeds and water plants.
Gradually, the tadpole starts to grow legs. At the same time it loses its tail. The tadpole now looks more like a frog.
When it is fully grown, it comes out of the water and starts living on damp land and eats insects, worms, etc. As an adult, it breathes through lungs when on land and through its moist skin when it is in water.