The textbook chapter 'सुंदरिया' encourages students to explore the sources of milk and the animals that provide it. The context mentions 'गौशाला' and 'डेयरी फार्म' as the primary sources for milk, while also listing 'गाय, भैंस, ऊँट' as the large animals whose milk is consumed. The story of Hirasingh and his cow Sundariya also illustrates how villagers rear cows for milk.