Reproduction is all about making sure that living things survive by producing near copies of themselves. In the case of humans, parents produce children which will grow up in turn, and many will have children of their own.

Humans produce small versions of themselves. These are babies. But many animals produce new life that looks very different from the adult. Tadpoles don't look like frogs, for example; dragonfly larvae look like beetles in the water, not like winged insects.

So all this goes to show that there are many ways to keep a species alive. The video below shows the tadpole stage of a frog.