Nicky conducted a lesson on ecology for IGCSE students, covering key concepts such as food chains, food webs, and energy transfer between trophic levels in ecosystems. She explained the challenges of measuring biomass and energy transfer efficiency in ecological studies, including the difficulties of counting mobile organisms and the impracticality of certain measurement methods. Nicky guided students through exercises on drawing energy pyramids and calculating energy transfer efficiencies, emphasizing the importance of understanding how energy flows through food chains in various ecosystems.