Work with nature is one of the key principles of permaculture design Putting massive effort into attempting to ‘tame nature’, such as by damming valleys and flood plains or creating and maintaining bare soil by plough, is not only energy consuming, unsustainable and destructive, it is also unnecessary when we can meet the needs of people and the environment by working in harmony with, or even directly utilise, natural systems. Instead of using massive chemical inputs to control pests, why not encourage predators such as ladybirds and hoverflies to do our work for us (see Biological pest control)? Or why not construct homes that utilise passive solar energy and wind power rather than building nuclear power stations?