Final answer:
John and Molly solved their snail problem in 'The Biggest Little Farm' by using natural pest control methods to encourage biodiversity, which allowed predators of the snails to manage the population.
Step-by-step explanation:
The question pertains to how John and Molly solved their snail problem in the documentary The Biggest Little Farm. This film chronicles the challenges and triumphs of the couple as they develop a sustainable farm. In addressing their snail problem, they utilized natural pest control methods, encouraging biodiversity on their farm. This approach allowed predators of the snails to thrive, who in turn helped to manage the snail population. In essence, Molly and John's strategy was to create an ecological balance where one species problem could be solved by the introduction of another species to control it, illustrating the complexity and interconnectedness of the various species within an ecosystem.