托福口语 Task 4

Today, we're going to talk about a fascinating behavioral adaptation in animals called 'shelter building.' Specifically, I want to focus on how some animals construct homes that not only protect them from predators but also help regulate their body temperature. Let me give you two examples. First, consider the beaver. Beavers build dams and lodges in rivers. The dam slows down water flow, creating a pond that surrounds their lodge. This water barrier keeps out most predators, and the lodge's thick walls, made of mud and wood, provide excellent insulation. In winter, the water under the ice stays at about 4 degrees Celsius, which is warmer than the freezing air above, so the beaver can stay active and safe. Second, think of the African termite. Termites construct massive mounds with intricate ventilation systems. The mound's structure allows hot air to escape through the top while cooler air is drawn in through lower openings. This natural air conditioning keeps the internal temperature stable, around 30 degrees Celsius, even when the outside temperature fluctuates drastically between day and night. So, in both cases, the structure is key to their survival.