Answer the following question given this paragraph: 

This caterpillar is busily munching its way through leaf after leaf. In fact, caterpillars do little more than eat, day and night. Like all living things, they need food to provide their cells with energy. The caterpillar will soon go through an amazing transformation to become a beautiful butterfly. These changes require a lot of energy.


Q: Transforming from a caterpillar to a butterfly requires a lot of what?


A:
energy