TOEFLリスニング

🎧 リスニング原文

Listen to part of a lecture in a biology class. The professor is discussing the behavior of social insects. Professor: Today, we'll explore the fascinating world of ant colonies. You might think of ants as simple creatures, but their colonies operate like superorganisms. Each ant has a specific role. The queen lays eggs, workers forage for food, and soldiers defend the nest. But how do they coordinate these complex tasks without a central leader? The answer lies in chemical signals called pheromones. For instance, when a worker finds food, it releases a trail pheromone that guides others to the source. Interestingly, recent studies have shown that ants also use pheromones to regulate colony size. If the colony becomes too crowded, certain pheromones inhibit the queen's egg-laying. This feedback mechanism ensures resources are not overexploited. However, this system is not foolproof. Environmental changes, like habitat destruction, can disrupt these chemical signals, leading to colony collapse. So, while ants seem to have an efficient system, it's also delicate, reminding us how interconnected species are with their ecosystems.