The story of 'Ruby Flew Too' makes a great context for learning about life cycles. Where do ducklings come from? Are ducks viviparous or oviparous? Do baby ducklings look the same as big ducks? Why did Ruby fly away? What happened when she came back? What about other animals? Below you can find different resources for teaching the language and content to young children.
You could also make your own worksheets for children to draw or even tell them the story of 'The Ugly Duckling' to illustrate how some animals change as they grow up.