The document discusses how environmental changes can be used to change behaviors. It provides three examples of target behaviors and the environmental changes that were made to influence each behavior. For the first behavior of looking at a task list more often, changing the home screen on a phone worked because it tapped into an existing behavior. For the second behavior of flossing after brushing, just putting floss by the toothbrush did not work because the trigger alone was not enough and flossing was difficult and painful. For the third behavior of walking 30 minutes per day, leaving a bike far away worked to force the behavior by removing alternatives.