The phrase "frog pond" means a small body of water where frogs live and make their sounds. It can also refer to a place that is crowded or full of people. Full definition
As for the benefit that disadvantaged students draw from such mixing, Wax observes the «frog pond effect» whereby poor youngsters placed in more affluent institutions tend to lose out in the competition for grades and social standing, resulting in lesser self - confidence and emotional well - being. (educationnext.org)
• Removal of non-native Monterey cypress and Monterey pine trees at the lower end of the Green Gulch pasture to make room for a California red - legged frog pond and to create large woody debris for the new channel. (parksconservancy.org)