I love silkworms -- it's amazing how these little critters can eat mulberry leaves and turn them into silk! They're definitely not to be taken for granted. Feed them with red cabbage and get a multy color poop.
This is an example of how living things grow and develop. The caterpillar goes into a cocoon then comes out and has turned into a butterfly. The caterpillar turns into something different than it was before and it is doing different functions.