Now, why would an engineer care about a food chain? Well, because engineers are interested in everything that involves energy. It is the job of engineers to come up with new fuels and ways to conserve the energy we already use. Many types of engineers — chemical, mechanical and civil — work on projects that use energy flow and transfer. Energy efficiency (saving energy) and energy sources are incredibly important fields as everyone wants to find ways to use fewer natural resources, such as trees and fossil fuels, as energy sources. Can you name any renewable energy sources? (Examples: Wind, water and solar.) Engineers also investigate foods and how they grow and supply us with energy. Engineers look at how energy moves through a food chain and use that understanding to develop other energy technologies, even biodomes and space stations. Engineers ask questions such as, "How much energy is needed to grow plants in this environment?" and "How much food is needed to provide enough energy to the organisms or people living in this environment?" Those are some pretty important questions!